Some time before and during Pinkie Pie’s reaction:

-TERRARIA, YHARIM’S KINGDOM: ARENA-

Conflict continues to roar out on the arena’s field as Skeletron, fused with the symbiote, Toxin, battled against the Kitsune Tyrant. As this goes on, the crowd began to erupt into celebration as a new spectacle took place before their very eyes. However, among the large crowd were Crystal Moonbeam, Sweetie Glutonia, Princess Cadence, and the terrarian Tirek.

A river of tears was strolling down Crystal’s face as she comments:

“MeMe… I’m so sorry…”

Sweetie Glutonia places her right hand onto the small kitsune’s right shoulder, “Crystal… I need you to stay here. Don’t you dare move from this spot, do you understand me?” She emphasizes as she points a finger down towards Crystal’s current position.

The kitsune’s ears perk up, “W-where are you going?”

“I’m going to help Statis and Braelor. We need to get Pinkie Pie’s life force away from Yharim,” Sweetie Glutonia responds. “We mustn’t let Mena’s sacrifice be in vain, we still have a job to do.”

“What about her?” Princess Cadence questions as she points towards Cosmos, who is currently dodging the skeletal appendages of Skeletron, “What if she manages to defeat those two and targets Crystal? I’m ashamed to admit it, but Calamitas drained my powers during my capture, so I won’t be strong enough to defend us.”

Tirek shrugs, “And I’m too clumsy to be effective in combat.”

Sweetie chuckles, “Oh no, you two misunderstand me,” She then pats Crystal’s head lovingly, “Crystal will be the one to defend you both, but I don’t want her to follow me so I’m telling her to stay with you.”

The daughter of Greed then looks into her half-sibling’s eyes, “Crystal, I want you to protect these two while I go to help your uncle Yharon and our friends, ok?”

“B-but… what about daddy?” Crystal responds, referencing her father figure: Yharim.

Glutonia bites her lower lip in hesitation, and sighs sadly, “I will try my best to help your father, ok?” She responds.

Catching onto her hesitation, Tirek blinks twice and questions:

“Did you just lie to her?”

Both Sweetie and Cadence glared at him with facial expressions that translated to: ‘Shut up! You’re not helping!’ He scratches the back of his neck nervously and says:

“Shutting up.”

……….

Cosmos flew high into the air as she looked over her left shoulder, only to see the encroaching form of Skeletron’s skull which bared its changed fangs thanks to the symbiote.

“Time to eat!” Toxin exclaims while Skeletron’s voice could be heard roaring in tandem.

The skull threatened to bite the Kitsune Tyrant clean in two, but at the very last second before the largest fangs of Skeletron’s maw could make contact, Cosmos disappeared with a snap of her right paw. A cloud of strawberry milk mix was all that entered the skull’s mouth, the taste of strawberry quickly meeting the entity’s taste buds. A perk granted to the skull thanks to Toxin’s merger.

“Eugh!” Toxin exclaims in repulsiveness, “Disgusting!”

“Stop fucking around, Toxin!” Skeletron exclaims. “She’s reappearing somewhere else.”

With a resounding ‘POP’, Cosmos appears high above the unified form of Skeletron and Toxin. She aims a single index appendage of her right paw and shouts:

“Time to kill you for good this time, Grogar!”

“The fuck’s a Grogar?” Toxin questions.

“Old name, long story,” Skeletron responds bluntly as a large barrage of energy projectiles is let loose upon them by the Kitsune Tyrant.

The skeletal-like entity elongates its flesh upwards as a wall composed of Toxin’s alien flesh and Skeletron’s bones shield them from the kitsune’s assault. The being smirks as it controls its two large arms with clawed hands upwards; en route to contend with the kitsune as the appendages also dodge her attack.

The two appendages attempt to swipe at Cosmos with their claws, courtesy of Toxin, but the Kitsune Tyrant conjures forth two identical blades to block their attacks. Notably, these blades were two separate Blood Butcherers. A struggle of physical might ensues as the skeletal-fleshy appendages try to press against the newly conjured blades.

Cosmos grins and raises her right paw, “Annoying sack of bones, I’ll just have to deal with your main skull!” She snaps her paw and vanishes once more, reappearing beneath the wall of flesh and bones that shielded Skeletron and Toxin from her barrage. Said barrage ceasing as she does so.

“And now you di-” Cosmos’s words are cut off as her opponent was gone, vanished without a trace. The wall provided her foe the means to hide without being seen, “What? Where did they- graugh!” She suddenly shouts in pain as a large skull covered in Toxin’s flesh erupts from the ground and strikes the kitsune. In addition, the skull slams her against the wall of bones and flesh that were floating above her, giving the skeletal entity a convenient foundation to crush her against.

“I’ll squash you flat!” Skeletron exclaims. “Toxin can devour whatever is left of you!”

The tongue of the skull created by Toxin licks its teeth as if it had lips, “Mmmmm, you look tasty!” Toxin shouts with excitement.

As she was being crushed by the skull’s might against the wall she was being forced into, Cosmos suddenly smiles devilishly and comments:

“You’re not the only one who can play tricks, Grogar,” An orange aura flashes in her eyes, “Here’s a fun fact: I’m just a clone.”

Another Cosmos, the real one, appears behind the skeletal entity with her right paw aimed towards them, “Time to seal you two up with your dead master!” An orange aura surrounds her appendage which, in turn, consumes the form of the skeletal; alien fleshed entity.

“Dammit, all!” Skeletron exclaims.

“Ah, shit! Welp, we did our best, Skelly-Boy.” Toxin said.

“Don’t you call me that you wretched alien-” Skeletron’s words were cut off as the duo were forcibly morphed into a sphere of energy. Cosmos then conjures forth a very particular staff and guides the spherical energy into it. Incidentally, this was a Staff of Necrosteocytes.

Looking at the staff before her, Cosmos chuckles mockingly before tossing it away. The staff was thrown into the crowd, but towards the direction of Princess Cadence who managed to catch it in response.

The entire arena roars out with amusement, and Cosmos soaked it all in while exclaiming:

“Behold! I am the strongest being ever to enter this arena!”

……….

After catching the staff, Princess Cadence wields it in her grasp as Tirek and Crystal Moonbeam looked onto the Kitsune Tyrant with their own reactions.

“I absolutely despise you, ‘mother.’” Crystal said with absolute venom in her tone. “Your victory is a shallow one…”

Tirek looks toward the angered child, “Maybe you can try hugging her?” He questions. “Maybe she’ll feel better? At least, that’s what I heard happens when you hug someone who’s mad.”

Cadence facepalms in response, while Crystal’s eyes shoot towards Tirek with a red and black aura consuming them.

“I would sooner gouge out my own eyes before I ever hugged her,” Crystal finishes with a growl.

……….

Out on the field, Cosmos continued to bask in her glory as she then floated high into the air and looked down upon the form of Pinkamena. She leaned against her right claw as if she were lying down on the floor and comments:

“Ah, it feels so good to be me,” The Kitsune Tyrant conjures forth an unlighted cigar, holding it between two of her claws, “Game, set-”

“Ooh, ooh, let me guess this one! Ummmm… Match?” Says a strangely high-pitched voice.

Present:

Cosmos’s eyes shot wide open as she dropped the cigar in her grasp from pure shock. Looking down, a sense of confusion overtakes her as Mena’s form seems to be unchanged.

“I’m right, right? I have to be right! It’s a tennis reference, right?!” The voice continues.

“What is this? A side effect from those flames? How are you in my head?!” Cosmos responds with a talon to her temple.

“I’m not, actually, but I could be! Oh, I should probably tell you I’m nearby, too! Can you find me?” The voice giggles.

The kitsune growls, “What are you going on about?! You’re still down ther-” Her words are cut off as the dark pink pony’s form was now missing.

“Am I?” The voice asks, still with the usual high-pitched tone, yet with a slightly crueler undertone.

……….

The crowd was now silent at this spectacle, many whispers and questions building up among the masses. Crystal Moonbeam, Princess Cadence, and Tirek look on in shock as The Princess says:

“I… I should be glad that Mena is ok. But, why does it feel so-”

“That’s not my sister… not anymore,” Crystal comments with a shuddering form, “Someone else has taken over her body… I can feel it.”

Tirek scratches the back of his head in confusion, “Wait, so does that mean she’s alive or still dead?”

“-Oh, I’m technically both!-” The voice of the dark pink mare responds gleefully, echoing to the minds of the trio, “-You’re all probably really confused! But to give you the short version: I am Pinkamena! Not that sappy Mena who kept me contained for Abaddon knows how long, but the real deal! Oblivion fucked up big time in his desperate attempt to save her, hehehe!-”

Crystal’s fur rises and shifts in response to her anger, “You’re not MeMe! You’re just a mistake that she had to correct! My sister told me all about what she and Pinkie Pie had to do in the GrimDark!” The small kitsune stomps her right foot in defiance, “You’re not her, so stop pretending to be!”

The voice pretends to be hurt, letting out a feignedly ‘gasp’ before saying:

“-Awww, how rude of you to say such a thing.-” Pinkamena chuckles, “-I suppose you’re right, though. Mena was born here in Terraria, but I was born into the GrimDark. Multiverse theories’ a bitch, ain’t it?-”

“Does anyone else hear the high-pitched voice in their head?” Tirek questions while blinking his eyes in confusion.

“-...Ok, this guy’s a dumbass.-” Pinkamena comments, annoyed by Tirek.

“We will stop you!” Princess Cadence exclaims. “Your kind will never threaten this world!”

Pinkamena’s high-pitched laughter echoes within their minds, “-Are you stupid or something, Princess? We’ll never threaten the world? We’re already here! Abaddon’s will has made it so!-”

“W-what?” The Princess questions in disbelief.

“-Ugh, I hate explaining things! So I’d rather show you what I mean. Now, if you’d all be so kind as to turn your attention to the field.-”

……….

Cosmos begins to throw her head around, even literally, as she searches for the missing pony, “Stop hiding and get out here!”

“Oops! Sorry, I had to make another call! I gotta say: You’re really bad at this. And who said I was hiding?” Asks the voice cheerfully.

Cosmos grunts in annoyance, “Then come out and face me! Or are you too scared after that little strike I gave you?!”

The voice begins to giggle maniacally, shedding the previous happy-go-lucky tone and replacing it with a sadistic one instead.

“If you insist…” It says as Cosmos feels an ominous presence rise up behind her.

The Kitsune Tyrant’s eyes widen as her mouth forms into an ‘O’. She slowly looks over her right shoulder, only to see nothing there.

The voice bursts out into a fit of giggles once again, “Oh, Oh! You should have seen your FACE! That was priceless!”

The Kitsune clenches her claws so tight in both anger and annoyance that she punctures her palm in the process. Her own blood drips from her paws as she shouts:

“GET THE FUCK OUT HERE!”

“Awwww, I didn’t mean to make you mad… Well, I mean, I totally did, but still! There’s a knife about to stab you in the side by the way,” The voice chirrups as a gleaming butcher’s knife fires forth.

An elongated slash was now present on Cosmos’s form, stretching from one end of her abdomen to the other.

“Oops! Sorry! I meant to stop that one before it hit you but I missed it! Hope it didn’t hurt too bad.”

“I-I’ll just heal it off you stupid pony!” Cosmos exclaims as she snaps her right paw, causing an orange aura to surround her form which instantly mends her wounds.

“Oooohhh… You can heal yourself?!” Says the voice excitedly before it transfers to a tone full of bloodlust. “You’ll be a GREAT ingredient investment…”

“Ingredient?! Get out here so I can stuff you into a cake!” The Kitsune Tyrant roars out, seething with anger, “I WILL NOT TOLERATE THESE CHILDISH GAMES!”

A floating white smile appears in front of Cosmos, followed soon after by a shadowy pony silhouette.

“Speaking of cake… do you like cupcakes?”

With little more than a gentle whisper, the shadows of the arena begin spinning, condensing into a singularity around the silhouette. All the while, the white smile stands out brightly, visible even through the darkness cloaking it.

“I always did like the dark,” Pinkamena states. “Not as much as Pops though. Actually… Let me put him on the line for you.”

The darkness explodes outwards, glowing an eerie red now as what appears to be a portal opens inside of the swirling mass.

Within the anomaly, an almost equine figure composed entirely of choking darkness gazed back at the combatants; causing Cosmos to be instilled with fear. The entity was the living embodiment of the saying: ‘Stare into the abyss, and it stares back.’ Six shadowy purple-colored energies acted as the being’s ‘eyes’. A series of purple shadows act as the entity’s wings, tail, and mane, in a similar fashion to the Pony of Shadows.

“Ahhh… I see light before my eyes. A sense of familiarity stands before me,” A deepened voice comments from beyond the veil, echoing in a fashion similar to Polterghast, “Is that you, Mena?”

“It’s me, Pops! But didn’t I tell you that’s my party pooper self’s name? I don’t use it in this form.”

Abaddon’s voice chuckles within the abyss, “Names are a powerful thing. It is unwise for me to use it so casually, especially in your current predicament.”

“Truuuuueeeee…” Says Pinkamena, putting a shadowy hoof to her chin. “But it’s not the name YOU gave me, Pops!”

“Indeed… So, what have you called the darkness for, Pinkamena? We’re preparing to invade this world, and Rainbow.EXE is rather excited.”

“I wanted to borrow some of your power! I have a delicious treat I want to make…” She says, staring at Cosmos and licking her newly-revealed fangs, a bit of saliva dripping off them.

A series of deepened laughter echoes within the anomaly as tendrils made entirely of shadows seemingly drips and elongates out of the portal, “You know me all too well, my dear,” The lavender eyes of the black entity fixates on Cosmos, “Come, Cosmos, come to the darkness…”

A fit of giggling overtakes the pink mare as she prances to her father, waiting by his side.

Recovering from her absolute sense of fear as the tendrils wrap themselves around her, Cosmos stutters and strugglingly shouts:

“N-no! I will not go in there with that thing!”

“My father and I are hungry, Cosmos… One way or another…” Pinkamena says as her smile widens impossibly. “We’re going to eat for the first time in millennia!”

Abbadon chuckles, “Welcome to the GrimDark, Kitsune Tyrant.”

The mare giggles maniacally as she gets ready to pounce on Cosmos with what appears to be some form of claw on her hooves.

“Enjoy your stay…”

The dark tendrils of Abbadon pull the screaming and struggling form of Cosmos into the anomaly, Pinkamena hopping into it afterward. However, one of the tendrils seems to stab itself into the arena as darkness starts to creep into the soil. It looked and acted similar to the infectious spreading of The Crimson, or Corruption.

“We shall leave you all a parting gift... Reject the light, embrace the darkness.” The voice of Abaddon says before the anomaly closes behind the now retracting shadowy limb.

Screams roared out from the crowd, and Yharim’s guardsmen began to combat against new enemies that were being born from the shadow-covered arena.

-TERRARIA, THE VOID-

Venomous Sting, or Sagittarius as he was now known, appears to be muttering to himself in an annoyed fashion, collecting several pony-sized items from a floating island within The Void.

“Can’t believe- Bloody ponies- Wish I could kill them, but noooooooo…”

“Hello, Venomous… It’s been a long time.” Abbadon’s echoing voice said.

“EH?” Venomous growls, looking around. “Look, Abaddon, I don’t have time for this! Let me make it clear: No, I’m NOT going to let your shadow take me over.”

Abbadon chuckles, “Unfortunate. You’re not as fun as Luna or Rarity, but that’s not why I’m here…”

“If you’re planning on fighting me with the slaves you call your children, you can shove it up your ass!” Venomous shouts with a growl.

“Venomous, would you like to see your mother again?” Abbadon questions.

“Hell fucking no. Besides, she’s locked away inside that weird-ass dimensional hopper you kept talking to me about. Mena and her sister, Pinkie Pie.”

“I’ll let her do the talking.” Abaddon responds as a certain dark pink mare appears from a puddle of shadows.

“Ooh! Hiya Venomous! I missed you!” Giggles Pinkamena, throwing a partially-eaten, but alive, Cosmos on the ground.

“Oh for fuck’s sake. I sure as hell didn’t miss you.” Venomous responds in disgust.

Pinkamena recoils in mock pain, “Oh, you wound me so! How’s Silence by the way?”

“Fuck. Off.” Venomous retorts.

“If you two are done with your little family reunion,” Abbadon comments. “You have business to attend to, Mena. You are to rendezvous with Rainbow.EXE and the others.”

“Oooooooohhhh, sounds like a bitchin’ good time to me!” Pinkamena squees, disappearing soon after as the words: “See you later, son!” Fades away slowly while also echoing throughout the local area.

Abaddon fires up his blackened horns and lifts Cosmos into the air, a blackened aura surrounding her injured and maimed form. He conjures forth a shadowy anomaly, Terraria on the other side of it, as he comments:

“I thank you, Cosmos. Your actions have caused the appropriate events to free the GrimDark,” The Ancient of Darkness tosses Cosmos’s serpentine form into the anomaly, “I shall spare your worthless life as compensation.”

The anomaly closes moments after the Kitsune Tyrant is thrown in as Abaddon looks towards Venomous Sting.

“What do you want,” Venomous grumbles, glaring at Abaddon. “Dad wants me to go protect a bunch of random ponies, so, hurry it up.”

“Do you not sense what has happened? Why I am finally able to roam free throughout the GrimDark?” Abaddon questions.

“Yes, I do, but I couldn’t care less about you or that prick who calls me her son,” Venomous said.

Abaddon chuckles, “Ah, the defiance of a child. You almost remind me of my Sombra. Pinkamena isn’t my actual child, but what she is now, is what my son should’ve become. Anyway, both the GrimDark and The Void have returned to Terraria… and so have I.”

“Thanks, Captain Obvious. I couldn’t tell that the GrimDark came back by Rainbow.EXE jumping out of the fucking sky, not at all.” Venomous says dripping with sarcasm.

“Ah, yes, Rainbow.EXE. A fine specimen of the GrimDark, but still has much to learn. Also, you’d do well to watch your tone with me, BOI.”

“How long did you spend building up your fat ego again?”

“Ego is for fools such as yourself, Venomous. I simply know what I am... all powerful.”

“Like I said. E-G-O.”

Abaddon laughs in response, black energy surrounding his form, before saying:

“Have fun out there… And spread the GrimDark’s influence well, you defiant fucktard.”

“So much black... I get it, you’re sad.” Venomous mocks.

A series of laughter slowly fades away as Abbadon’s darkness blends into The Void itself, causing him to disappear.

Venomous rolls his eyes, flipping Abaddon off with a middle feather from his right wing.

“Fucking Cthulhu wannabe. You’re heading straight back into the sin bin when Dad and the others finish with you,” He mutters, picking up his last item and transporting himself out of The Void. “Also, fuck you. I have to make my Sagittarius form have an ego. That’s what the original had before I ripped out his circuits. It’s called acting, asshole.”

Character inventory/equipment:

Fluttershy: Statigel Armor(pony, equipped), Overloaded Blaster, Eviscerator, Crimslime Staff, Corroslime Staff, Slime Staff, Finch Staff, Snow Flinx Staff, Hornet Staff, Blood Clot Staff, Deathbringer Pickaxe, Blood Lust Cluster Axe, Healing Potion, Honey Comb(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Honeyed Goggles, Slime Mount, Staff Of Necrosteocytes, Purified Jam.

Rainbow Dash: Necro Armor(pony, equipped), Star Cannon, Minishark, Eviscerator, Aquatic Discharge, Bloody Rupture, Deathbringer Pickaxe, Blood Lust Cluster Axe, Healing Potion, Aero Stone(equipped), Brain Of Confusion(equipped), Bone Glove(equipped), Mana Polarizer(equipped), Victory Shard, Slime Mount.

Zecora: Crimson Armor(zebra, equipped), Dune Hopper, Sausage Maker, Beenade, Tooth Ball, Aorta, Deathbringer Pickaxe, Blood Lust Cluster Axe, Various Potions, Rocket Boots(equipped), Honey Comb(equipped), Sand Cloak(equipped), Brain Of Confusion(equipped), Bloodstained Gloves(equipped), Bone Glove(equipped), Mana Polarizer(equipped), Honeyed Goggles, Skeletron Hand.

Starlight Glimmer: Meteor Armor(pony, equipped), Space Gun, Starfury, Vein Burster, Purple Phaseblade, Deathbringer Pickaxe, Blood Lust Cluster Axe, Mana Potion, Healing Potion, Victory Shard, Rocket Boots(equipped), Aero Stone(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Bone Glove(equipped), Slime Mount, Book Of Skulls, Skeletron Hand.

Rarity: Meteor Armor(pony, equipped), Space Gun, Hornet Staff, Snow Flinx Staff, Ice Mirror, Blood Clot Staff, Deathbringer Pickaxe, Blood Lust Cluster Axe, Mana Potion, Angel Wings(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Slime Mount, Book Of Skulls, Skeletron Hand, Staff Of Necrosteocytes.

Applejack: Crimson Armor(pony, equipped), Vein Burster, Orange Phaseblade, Deathbringer Pickaxe, Blood Lust Cluster Axe, Rope, Metal Detector, Healing Potion, Angel Wings(equipped), Honey Comb(equipped), Flurry Boots(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Honeyed Goggles, Slime Mount, Bone Glove, Skeletron Hand.

Twilight Sparkle: Meteorite Armor(pony, equipped), Space Gun, Book Of Skulls, Deathbringer Pickaxe, Blood Lust Cluster Axe, Mana Potion, Ichor, Victory Shards, Aero Stone(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Slime Mount.

Pinkie Pie: Crimson Armor(pony, equipped), Vein Burster, Blue Phaseblade, Bloody Rupture x2, Aorta, Deathbringer Pickaxe, Blood Lust Cluster Axe, Metal Detector, Angel Wings(equipped), Honey Comb(equipped), Flurry Boots(equipped), Brain Of Confusion(equipped), Mana Polarizer(equipped), Bone Glove(equipped), Honeyed Goggles, Slime Mount, The Blood Butcherer, Skeletron Hand.