The room went silent after a minute Emerl asked that question it left the sisters puzzled. They had questioned the first part of the question as the second part seemed logical since power can not be given/earned without a price. Luna was clearly lost to that question as they gave their purpose to the Guardian, yet Celestia is giving an analytic viewpoint.

“Why asked if we had told you back in the cave?” Luna questioned with uncertainty on what the robot demanded.

“Well Luna you never gave me a clear answer, since I have never meet Discord to give a proper reason to stopping him.” He pointed out without a care to their shocked reaction. “Besides if I do give it to you it would seemed as if you guys will brag to the other species in defeating Discord.” His eyes gave a dim glow at the next sentence. “I need a clear answer that will convince me that ponykind wouldn't abuse the power of Harmony.”

Luna seemed insulted that a magical construct claimed that ponies will abuse the powers given. In Luna's opinion, the most expected species with an abuse of power would be mostly dragons, since they were big greedy flame breathers. The size and power of a dragon are usually based on their hoard size and based on what her sisters encounter. They would nearly fight to the death for the crystal heart if she had not shown intimidation. Celestia is still mauling over the purpose of the question.

'Why would a guardian of Harmony question our use of power if the purpose is to rid of their opposing force? The opposing force that can kill his charge if it was ever discovered.' Celestia thought deeply as she focus on the properties of Harmony and Chaos.

“Emerl ponykind would never abuse the power! We have the power over the sun and moon, yet we have been most sane and well-mannered as a princess should be.” Luna proudly boast on their care and abilities to protect and guiding the kingdom.

“Luna you have corrupted nobles in your government and your society is based on mostly noble matriarchy. That means most of the stallions and commoner mares would be treated as servants at best.” Emerl grimly pointed out with a hidden anger in his eyes at their ignorance. The princesses didn’t picked up his eye color as they disbelieve his claim.

“Nonsense our subjects are happy with our rule though you have a point that there are corrupted nobles, yet our subjects are treated fairly.” Luna retorted thinking their kingdom is a utopia, yet the sun princess knew the truth was that corruption is always exists in a system.

“I know some of your subjects are joyed with your rule,” He tried to calm the moon princess before pointing out something crucial of their ponies main flaw. “yet any troubles that involve foreigner subjects would come back and bite you in the ass.” He expected they may deny what he was about to tell them. “Some pegasi attempted to kill a griffon for believing more towards their own belief than the entire tribe’s which is worshiping you two.” Just as he expected the moon princess shook her head in disbelief at the robot’s words.

“They must be some type cults that will be executed once found or you're a liar. We have never heard of such tales during our rule.” Luna raged at the robot’s accusation.

“Wow you are really naive if you think your ponies are innocent with each other.” Emerl retorted with a dark tone while giving an ominous glare at the moon princess. “I can show you some of the horrible things your ponies have done after I hear the answer to my first question.” Luna was hesitant on the offer before she focus back towards the question he asked earlier.

'The power of harmony can surely counter the powers of chaos, yet what can counter the power of harmony.' She gained a quick hypothesis. ' It can be estimated that chaos can counter harmony and vice-versa, so they either depend on each other to make a balance on the world or this robot must believe in equal judgment. I believe this Emerl will-' Celestia's thoughts were interrupted by Luna's answer.

“The answer is obvious we should receive this power to stop a deranged psychopath from causing mayhem on the world.” She stomped her hooves to give a clear point towards their duty. “As the rulers of Equestria we should be able to hold the responsibility to uphold harmony needed for the world. We have experience from our travels to know that if we share with others it can lead to new discoveries.” Luna closed her eyes and continued with determination toward her words as she continued.

“If we had to sacrifice anything from our lives it shall be our hatred. As hatred is the one thing that everyone drives apart from one another which should be given up for a lifetime of happiness. Hatred is a cycle that can bring pain for all unless someone can break it.” Luna had given a smile for her response as Celestia was a lost of speech before smiling proudly at her sister’s words.

Emerl had to give credit for Luna to giving a decent answer, yet it lacked the realistic principle that he was looking for. Harmony gave a smile indicating she will accept them as her wielders for the Elements regardless what happens, yet Emerl wants to see the special flare that makes these two ponies above the other races. Celestia gave her sister a proud look that she has taken her lessons to heart. He is awaiting for Celestia to give her answer.

“Based on your reaction when we first met, you did not care who or what tries claim the power you are guarding as long as they are worthy to wield it. The point of harmony is similar to what Luna had described, yet we can not disregard the negatives as we keep the positive. Hatred helped others to flow together as happiness, since it is the struggles we endured and common interests to help one to achieve what is right. Hatred is a part of us that we have to embrace, yet never let it overcome as happiness and bonds keep them in track. Once these forces achieve balance, they will achieve to what we have as harmony. I may not need to sacrifice anything, yet to give time and effort to earning the award that life provides. ” Celestia declared with beaming eyes towards the truth of the manner.

Emerl was impressed that the princesses can conclude a good estimate to what harmony can be and decides to ask a question for their last trial.

“ Well girls, I am impressed by the answers you have given, so I will give an advice.” He cross his arms while his robotic eyes glowed for dramatics. “The quality of the being is nothing compare to the quality of their soul as each individual are judged by their actions either to help or destroy. Can you face the shadows you have buried or let it consume your soul for hades to enjoy?”

“ Emerl are you suggesting that we have to face ourselves as part of the test?” Celestia asked while raising an eyebrow.

Before Emerl can respond to Celestia's question, Harmony threw a pillow in his face for attention. The robot was about to retort until he notice a sad look in her eyes meaning it's going to relate to her past and who is he to deny. He decided to give Harmony her words before finishing this trial as it's not his place to decide who can use her powers. The magical earth pony cleared her throat as she softly began her speech.

“My mares I have a legend to tell as you know mortals have always crave power even though they have strength to prove themselves. What you don't know is that immortals can sometimes lead the same mistakes as mortal do.” Harmony grined a bit on that statement with the amount of false immortals to actual immortals being binded to the limitations of mortality.(Thor) “This immortal was a protector similar to you two. The power to protect can be awesome,” She gave a frown on the next following words which the sisters paid attention for. “yet if there isn't a balance to counter the wielders of this power it converts to a power of destruction. The wielders would turn against those they sworn to protect and seek only to self-satisfaction.”

“Are you saying that my sister and I would have been mad with power if someone like Discord haven't showed us humiliation?” Luna questioned the entity’s declaration with narrowed eyes.

“Well that would be true if you mares would have eventually attempt to kill each other, since most of your subjects respect Celestia than Luna.” Harmony stated without a care.

“How dare you! I know our subjects have expressed their love equally for us!” Celestia exclaimed subjectively to the declaration before the mare entity glared harshly at the sun princess.

“Tell me sunbutt how come most of your subjects only stayed inside when the moon and stars shines in the sky?” Harmony retort back with a dark tone. “I know it's for safety for the young, yet the adults have feared the night when Luna have given her effort to protect them.”

“What did you expect the creatures of the night would calmly welcome my subjects with treats instead of claws through their bodies and Luna has protected them in their sleep.” Celestia nearly yelled with a furious tone while believing she was fair to her sister.

“Luna is able to protect your subject awake as she does asleep, yet you don't believe in her. In fact, if Luna told you her problems you would ignore her as you do to the nobles.” Harmony retorted back with equal force, which made the moon princess uncomfortable of the discussion.

Celestia only glared at Harmony for the disrespect she endured for the accusation that she was a horrible sibling. She decided to put what she assumes is a mud pony in her place. Their heads went close to each other, which anyone in the room could see the eye sparkles intersect with one another. The duo were ready to fight it out until they felt both their bodies floating in the air with an indigo aura covering them. They quickly turned to Luna whose horn glowed with an angry expression.

“Can you both stop talking as if I am not here?” Luna demanded the two while holding them in front her. “Sister we have enough manure to deal with Discord, so can we leave this issue at home once we deal with the threat.” She turned towards Harmony with a the same expression, yet her eyes had a bit of appreciation for what had done. “Sync Heart I know you are trying to look out for me, however this is family problems that only her and I will resolve. I would ask if you mind your own business.” The mare entity felt hurt by the Luna’s words, yet she nodded in acknowledgment. She could feel the blue mare being embarrassed by this argument and wanted to move on. “I want both of you to look each in the eyes and apologize.” Luna words held a serious tone of power, while her eyes held a stern grip on the two mares.

Both ponies looked at each other with nervous expressions, yet sigh and followed the mare’s demands for the sake of the mission. They gave each other a short apology and a short hug which made the blue alicorn satisfied by the resolve. Emerl could not help, but laugh at the situation. The robot could almost love the blue alicorn for bringing her priorities straight, while humiliating the two strong forces on the planet. If Emerl did not choose Fluttershy and Pinkie as best ponies he would definitely chose the dark cobalt princess. Luna put the two ponies down as they decided to gave each other space as Harmony prepared her tale.

The tale of the Chaos Emeralds and it's Guardian

There once was shrine filled with sincerity and peace as it was surrounded by seven pillars of stone, water, and life. The shrine was created to dedicate respect for a god guardian by the people who worship said being. The natives of this altar were pacifist to all that have visited the altar, yet their naive mind had lead to easy manipulation from those who seek to destroy the peace. However, the guardian of the altar always cease the interlopers before they attempt to do such acts. The guardian protects his people from danger, which they showed the creature love and worship for his hard work. The guardian was known to be merciless on those attempting harm to all he cares, yet he altered the memories of the ones he spared.

It was unknown when and why the creation of the altar was made, yet it was believed to hold treasure beyond any mortal eyes. Another can say this treasure had granted miracles for the lands to prosper, despite the challenge the land faced it always survived and flourished through. On top each pillar had seven glowing gems filled with absolute power to shape the reality of the world we live in as they were called the chaos emeralds and each of these gems granted the power based on the user's desire. The chaos emeralds origin are unclear, yet the desire of the power can result to the following: the user with the positive intentions can grant miracles against the impossible of odd while the negative causes unimaginable disasters that would made Discord’s seem like a foal. Luckily the emeralds had a controller to stabilize and neutralize their powers if it ever rampages.

The controller of these emeralds lies in the center of the shrine as it appears to look like an enormous version of the chaos emeralds. This green giant was once called the Master Emerald, which was protected at all cost for the people who worshipped the guardian god. It had the power to surpass the chaos emeralds, yet its flaws made it unusable to outsiders and can break easier with the right amount of force. To activate the power of this emerald, it required a chant past down by a guardian or someone with a deep connection to the emerald. It went by the following: "The servers are the seven Chaos. Chaos is power, power enriched by the heart. The heart is the controller. The controller serves to unify the chaos." The reason for the past terms is that these emeralds were warped into something different after a great tragedy.

It started when a tribe of warriors who lived near the shrine had been planning a strategy to conquer their enemies and keep the resources for the good of the clan. This tribe was normally a peaceful group of people until a recent leader decided to take charge and reign over the nearby neighbors of the village. They had conquered every village until a rival tribe appeared and used advanced technology to overpower the warriors. Due to the tribe’s disadvantage in the war, the leader grew desperate for a way to counter their rivals technology. The leader remembers his mother's tale about the power of chaos and suggests to steal them to their advantage. However, many members of the tribe were not convince to the leaders plan until the leader explained that the power is enough to ensure absolute dominance against any enemy. It would take time for the leader to fully convince the tribes to renounce a long tradition for the sake of success.

During the time of planning, the daughter of the leader who had follow her grandmother’s philosophy of peace went out from her village to explore. The young maiden had found the altar and tried to make friends with the people, yet they had fear the maiden would bring harm and fled before she could interact. It took some time until the people of the altar have gotten used to the maiden’s presence. The guardian had only stood from afar and prepared if she attempts to harm them. Eventually, the natives have decided to introduce the guardian to the maiden who tried to befriend him instantaneously. The guardian had been baffled by the innocences in this stranger, yet welcome it.

Nearly the upcoming of the tragedy, the young maiden had tried to sway her father from his plans to steal the emeralds, yet it had came in deaf ears as he had ignored her words. As her options grew limited, she decided to run toward the altar and warn the guardian about the upcoming invasion. The guardian was prepare for battle until the maiden had plead that she will try to resolve this in peace and convince her people from the atrocious plan. The guardian had given her plan a chance as she tried to convince others to join her choice, yet they were dead on toward protecting the village even if it means desecrating traditions of peace. The guardian had pity the maiden for being some of the few members from her tribe to have a pure heart from the greedy war that her people ignited. The maiden tried to convince her father once more only to be warned if she attempts to hinder their plans he will be force to rid of her as well. The people spread rumors of the maiden being a traitor by forsaking their people’s survival, which made her life nearly unbearable.

On the day of the invasion, the leader's daughter had opposed her father by defending the natives she had befriended and tried to reason her people. However, it ignited an inner rage as the leader told his warriors to charge and harm the native of the altar. The guardian had grew enraged at the tribe and decided to make an appearance which caused the tribe to only stare in disbelief of the monstrosity. The guardian began absorbing the power of the chaos emerald to form into a dragon like being capable of leveling the entire village. Before the guardian could continue its plan a dark aura surrounded the emeralds which caused them to grow equivalent size as the master emerald. The new form of emeralds were quickly engulf into the guardian which caused a metamorphosis to an abomination of chaos created by the dark souls of every foe the guardian had slain. The guardian turned monster had decided to used it's powers to manipulate the maiden's tribe blood into toxins. The toxins had slowly killed every member disregard of age with the exception of the maiden; despite the darkness in the guardian's heart he had hoped the maiden would stop him from destroying the world.

The maiden who witnessed the death of her tribe went to the Master Emerald and asked for it's help to stop the chaos. Instead of sealing the guardian it brought a creature from another dimension. This creature had a force to make all bow to her power as she asked about the situation. The maiden explained everything to the creature in the best of her ability. The creature have decided to confront the monster guardian who stared at them savagely. The creature wasn’t discouraged by the appearance as she unleashed her power upon him, yet it only caused small damage toward the beast as he easily defeated the creature. The maiden had once again asked the Master Emerald to assist the creature, yet it vibrated with a message indicating that it requires a sacrifice to perform the task in full. The maiden had thought long and hard before staring at the creature who was having trouble. In a heartbeat, she accepted sacrificing herself for the sake of her new friend. The Master Emerald glowed brightly and gave the mysterious creature the power needed to defeat the monster. After that she converted the monsters energy back into the chaos emeralds as she purge the evil from within.

The creature came to see the maiden's lifeless body with sorrow in her eyes. She used her magic to give the maiden a proper burial, then took the emeralds with her in hopes of preventing a repeat tragedy. She had decided to leave a mark legacy of the maiden by rising a invulnerable statue in her honor. She provided a story to tell the citizens about the maiden who save the world from greed of her people. The creature gave only one last look before she teleported the Chaos and Master Emerald from their world.

There were questions swarming through the minds of the alicorns. Celestia had found the whole tale close to the earth pony's life and Luna wanted to know more of this heroic creature. Before they could have a chance to ask, Harmony held her hoof in front of them and stared at Emerl.

"Can you do me a favor and check if chaos didn't spread it's influence over to the other countries?" Harmony asked the robot with a quiet voice.

"Um sure Har-er Sync,” Emerl replied before wanting to asking a question in return. “do you need anything else?" Celestia picked up the little clue as she raised an eyebrow.

'What was he about to call Sync 'har'? Mmm I wonder what they are really hiding?' Celestia thought with suspicion on their behavior.

'What the hell bro, you almost gave my identity away!' Harmony mentally scold to Emerl for almost ruining her secret identity.

'Sorry my mind was a bit off by the story,' Emerl apologizes with a sincerely tone before asking her 'you're going to explain more toward how you changed from a Master Emerald and possible spirit of a echidna girl to the current you, right?'

'Um Emerl I will explain after you come back,' Harmony suspicously stare at her guardian. 'but why do you think the the girl is apart of me?'

'Don't think I don't know about the Master Emerald usually keeps previous guardians' soul to guide the new ones.” Emerl thought suspicious of her shifty motives. “Besides I have this feeling you choose these mares because of a personal favor?' Harmony’s eyes glowed with a quick rage at the accusation.

'Don't judge me, I would have chosen anyone else if they were completely different from their mom!' Harmony growled at the robot, before calming down and tried to change the subject. ' Can you please go, while I finish testing girls in a classic P4 battle style.'

'Alright mare!’ Emerl told the mare entity with slight fear before asking a self question about Harmony’s predicament. ‘how did you change from a sweet girl to an annoying brat is beyond me.'

Emerl left the tree home, while the sisters were confused on Harmony's sudden change. She gave a sweet smile in a manner that predators have found worthy prey to feast upon. The sisters are starting to fear the earth pony as she say these lines.

"Well you're all mine bitches." Harmony gave an maniacal laugh before dramatic lightning could be heard.

Meanwhile at Castle Discord

There was the chaos king discussing his plans to a group of five individual he had chosen from the random dimensions he had went to recruit. His first choice was a dark robot replica of the interesting creature he saw in the woods. The dark copy was a ruder individual, yet it'll be exciting to see who will prevail between light and dark. His second was a easy bargain as the lavender skin red head immortal had agreed to serve him if he helped conquer the immortal's home. It was a cinch to stopping any outside help, especially the ring girl where she was dump in the similar role as his slave. 'She'll never replace big blue.' The third was hard to convince, especially when she was similar to Celestia except purple headed. However, she sang when he mention he could make her kingdom ever-lasting and he sweeten deal with a magical sword from the old king. The last pair were battle crazy crimson machines that he promised to give them the ultimate opponent to face and prove who was the better robot.

"Well is everyone caught up to my plan." Discord reminded the group as he snap a talon to cause raining ducks from the horizon.

"Yes you will draw in the robotic rat to the stadium and make him fight us individually, so you can absorb whatever pitiful power to fuel yourself" The redhead confirmed with a annoyed glare.

"We prepared the stadium to prevent his ability to manipulate time and limit his teleportation, which will force him to use more effort to his fight." The purple haired witch continued with a bored expression.

"Then if he even wins against everyone, I would take the fool out since we are similar to one another." The dark copy chuckled evilly on the thought of proving himself superior.

"If he falls then we would scrap his body and prepare the battle against those weak wing horned horses, which we shall spread more chaos to find more foes to fight. " one of the crimson machines pointed out.

"Yes that's the short summary, yet it will help for some small warm-up before fighting you guys." Discord finishes with randomly eating a piece of wood. "mmmm I have to get me more of this cherry." Discord sense a familiar force in his kingdom

"It's time for plan gem smasher to begin."

Author's Notes:

Well sorry for the wait I was thinking back and forth between Emerls future challenges and getting to the point. Plus, I had to give my sibling a good week of fun. Oops I forgot the intro for the history lesson

The next chapter I am thinking that Discord and Emerl will meet as Discord issues a challenge for the robot to compete, yet if he loses, quits, or doesn't show Discord will do something irreversible that can lead this story grimdark.
I have this feeling to act on Discord would be a cheshire moment without the cryptic troll. I would appreciate advice or someone who knows Discords best to edit his lines once I am done with the draft.
Other than that, I will hope to finish the chats that will lead to the battles.

The story Harmony told is based on sonic adventures DX as you guess someone tempered with the emerald to make chaos go more insane than usual. Plus the creature was Faust the alicorn or Fausticorn since she sorta fits. She converted the emeralds powers to the two know creations to contain the power: a crystalize seed and a baby draconequus.

Harmony wanted the princesses to open their eyes to the dark side of their kingdom before it leads the same results as the knuckles tribe.

Plus, I will get chaosxtikal as friends, sibling, or mates depending on the stories progress.
My blog on the progress of my story and other news: link
Can you guys guess the five sonic characters I used for his challenge
The last note is that if a displace wants to mix into Emerls battle as displace characters have a ' well ' history of entering at the best moments.