At Hornguard.

Sombra was advancing into the city. While Luna and Arantir still could raise the dead to fight on, walls crumbled, and the stream of dark crystal figures was endless as they stormed the ancient city. Arantir and Luna stood side by side, constantly raising troops and boosting them with magic. The two surrounded themselves with impenetrable magical shield which protected them from any harm.

"I doubt we can hold for long..." Luna said. "This whole area is—" she placed a well-aimed shot at a coming crystal dragon, breaking one of its wings "filled with darkness Sombra uses to his advantage. The hatred that reigned here for so many years—" she paused for a moment to raise a few tens of skeletons that immediately returned to combat "hasn't disappeared yet..."

"We shall hold this city." Arantir replied. "However much power Sombra has, we shall still stand. Andromalius is working, he must be. Whatever he does will bear consequences soon... It will turn the tide of—" he cast a spell that placed some mines on the field of battle "battle."

"And if not?" Luna asked with uncertainty in her voice.

"A battle such as this couldn't go unnoticed." the necromancer answered. "If I am correct, reinforcements shall be here soon." he added.

"Reinforcements?" Luna quirked a brow.

"Your sister should have noticed the events by now. If anything, she will be here soon to fight on our side."

Meanwhile, at Canterlot Castle.

In the inner courtyard, Celestia and fifty troops stood, all bearing steel plate heavy armor and carrying various weapons with them: halberds, spears, crossbows, and swords. A couple of ballistas were present as well.

"This is the time when you, Equestrian best defenders, are needed." the solar alicorn spoke to the soldiers. "While our citizens think they are safe and secure, the yet distant danger looms over our kingdom. The darkness of the worst kind — the evil darkness. It is filled with anger and ravenous hatred, it wants to leave not a single city of Equestria standing, it wants to destroy us. We cannot sit here waiting for our doom. Instead, we shall fight.

"I carefully chose you, and I am sure you are the best among the best. You shall help me defend Equestria and its citizens from evil. I'm not going to sugar-coat it — some of us may be severely hurt or even die today. But if we do not fight, the darkness will seep further into our lands, consuming and corrupting everything it can lay its claws on: our homes, our families, our friend.

"So, today we fight for the safety of our country and our citizens. Now, come with me, and fight well."

A portal appeared behind Celestia, and she entered it first. The troops followed her without hesitation, disappearing one by one into the portal. As the last soldier marched in, the portal closed, leaving the courtyard empty.

Andromalius stood inside a circle of crystals he found himself in, and that was a big surprise for him. One moment, he was walking through a hall. Another — he is standing inside the circle, right in its center.

Shifting in place, he looked around. His heart was pumping fast, his legs were shaking from the adrenaline, and he breathed out puffs of smoke. His fiery eyes scanned the surroundings, carefully examining each corner. He readied his weapon, but hasn't yet seen any reason to jump into action.

"Hello?"

Andromalius quickly turned around and faced young Sombra. However, it was not the demon Sombra was looking at. Andromalius frowned and looked around, expecting to see something else. But there was nothing but black void filled with static.

"A-anypony?" Sombra called, warily stepping forward, and his voice didn't have any echo. It was quiet, as if the darkness itself swallowed the sound. "I... I... Where am I?"

"Is this another of Sombra's memories?" Andromalius thought. "It makes no sense so far..."

The shadow pony walked inside the circle, looking for something or someone. His legs were shaking, his breath was shaky, and his eyes darted around like crazy. A few minutes later, the vision disappeared, and the hell stallion found himself in another hall. Frowning, he walked through it to the next door.

Suddenly, chains wrapped around the door, and a big lock secured them. Loud metallic screech appeared, almost deafening the hell stallion.

Andromalius stumbled as he felt immense anger and fear as if they were his own. He wanted to smash, incinerate, vaporize, destroy everything he sees. The emotions stunned him and blurred his sight, he felt like thousand burning needles were piercing his brain in attempt to fill it with poisonous hatred. Visions flashed before the demon, too quickly for him to understand. And then everything around him faded, and two eyes appeared. Sombra's anger-filled eyes. They looked at Andromalius as if trying to burn a hole into him, to tear him apart, burn the parts, and scatter the ashes.

"Get. Out." the king of shadows spoke, sending shivers down Andromalius' spine. "Now."

The demon felt a strong grip taking hold on him, and then he was thrown out of the dark realm, and he appeared back where he teleported his friends away.

The weather was cold, the harsh wind of the Frozen North was blowing. But there was nothing lurking around, no evil to ambush Andromalius. It was surprisingly calm.

"We shall meet again, Andromalius." Sombra spoke inside the demon's head. "Until then, live. And may our paths not cross again."

In the last sentence, Andromalius felt fear coming from Sombra, as if it was not a threat but a plea. As his presence disappeared from Andromalius' head, the demon stood up.

"He somehow discovered that I was in his memories." he concluded. "What will happen now?"

The skies turned back to normal, the black crystal figures disappeared, and there was nothing but ringing silence among the ruins of Hornguard. The battle was devastating — many undead troops met their final death, some living reinforcements Celestia has brought has suffered injuries, including broken bones and harsh, scar-forming wounds. Some walls, one tower, and a couple of houses were completely destroyed by the battle, lying in a pile of broken bricks and dust.

The living were healing themselves, those who were severely hurt were being carefully taken care of. Overall, it became quiet, only hushed whispers could be heard as if their sayers were afraid of something.

Luna, Arantir, and Celestia stood together, looking at the horizon, seeing no signs of Sombra. None of them were harmed, only tired from the hard battle. It has been a long time since the alicorn sisters took part in battle, and this one was especially hard for them. Unlike Arantir, who was standing without even a sign of tiredness.

"Is he gone?" Arantir asked.

"Merely retreated. Why, though?" Celestia frowned. "What did Andromalius do to him to make him run away like this? It is unlike Sombra."

"It doesn't matter." Luna wiped the sweat from her forehead. Her horn was hot and red from all the magic she had to cast in combat. "Sister, we need to return to the castle. And nopony must speak of this battle to anypony else — our country won't accept us fighting with a necromancer at our side."

"We will have to talk about many things, sister." Celestia sighed, and then turned to her loyal soldiers. "Troops, gather everything, carefully lay the wounded on the stretchers. The battle is won, and we must return to Canterlot. Until I give command, none of you talk to anypony about what has just happened. The wounded must be treated in the Guard Hospital and not be brought outside the castle grounds. If families are interested in their well-being, tell them it is nothing major and that their members will return to full health soon. Unfortunately, we cannot tell the truth yet, as we all know how bad our citizens may react to these horrible news. I trust you, and I hope you trust me, too."

Andromalius stood in the open, breathing slowly. After the encounter with Sombra, he had to take a break before doing anything. His thoughts were in disarray, he still felt the sticky sensation of evil trying to take over him.

"Inanna, can you hear me?" Andromalius thought.

"Andromalius, I'm so happy to know you're alive!" the succubus immediately replied, and Andromalius felt happiness. "I knew you could do it! Whew, I'm glad Celestia and Luna took action..."

"Um, what did they do?"

"Well, teleport us back to yourself, we'll tell you. We can't wait to see you!"

Andromalius cast a spell, opening a portal to Canterlot. Soon, six ponies and one succubus went through it, and Inanna hugged the hell stallion quickly.

"I was so scared!" she admitted. "I am so happy to see you!"

"Me too." Andromalius hugged back. After the two parted, he asked: "So, what happened when I was away?"

"I certainly know that Luna went somewhere to distract Sombra so that you'd be able to do something." Inanna answered. "Twilight has seen Celestia doing something, too." she looked at the lavender unicorn.

"Um, yeah, I did." Twilight nodded. "Princess Celestia gathered a bunch of troops and some... ballistas, I think, and then teleported everypony somewhere. I've not seen anything like this before. Is it full-scale war with Sombra?"

"I don't think so." the hell stallion replied, shaking his head slightly. "I... I don't actually know what to think of Sombra. It seems he is a complicated... person. I've seen some of his memories. They are the key to why he became like this. I wasn't able to look deep enough to understand, he sensed my presence and threw me out. I think he fears me... He won't attack again for a long time. I suppose he is afraid of revealing himself."

"Um... I think I follow. You should tell the princesses about it." Twilight suggested. "As quick as possible." she added.

"I can send them a mental message, I suppose." Andromalius nodded, and then formed a message in his mind and sent it to the princesses. He knew he shares a connection with them, a special one. "Done. Now, maybe they will find out more than I did."

"That is... something. Nevertheless, I am glad that this is over. All of us were worried about you!" Inanna said. "Now, we'll just continue our way, right?"

"Yes." Andromalius nodded. "We still have a lot to cover. And maybe there's something else dangerous lurking in the north... We better be ready." he sighed. "Although, I think we have to spend another night here." he added. "I am tired... Not physically but mentally. My thoughts are in a mess... I suppose Sombra did that to me. So, tomorrow we move out." he finished his speech, sighing again.

Author's Notes:

It's been some time since the last chapter. I just didn't have enough inspiration to write this one, and the end is still kinda abrupt. But here it is nonetheless.
It was short, but I am glad it is finished. With it out of the way, I can return to the main plot.

I also decided that I won't reveal Sombra's full story right now, only some hints. And I think it would be stupid to just make Andromalius defeat him. After all, not everything is centered around the protagonist. Besides, there will be at least one sequel... You never know what will happen.