This is where I'm taking a significant deviation from the game's events. I'll explain why after the chapter.
Chapter 68 – The Umbral Beast (Red Wolf Moon)
The sounds of tearing flesh and the screams of men and women below immediately told the students something was dreadfully wrong as they advanced down into the Holy Mausoleum. As they neared the bottom of the stairwell, they saw a panicked man attempting to flee the area, being pursued by some sort of red tentacle that impaled him through his back. The tendril then ripped back, pulling the man screaming into the darkness.
Terrified, Annette said, "What was THAT?!"
"Something has gone dreadfully wrong," said Edelgard. "Are we too late?"
"Stay alert, everyone," said Jeralt as he readied his lance. "I'll take point."
"Right behind you, Jeralt," Anna said grimly.
The students, despite now being quite unnerved by what might be awaiting them, followed the Blade Breaker and the Secret Seller into the Holy Mausoleum. Once inside, they were met by a chilling sight.
In the center of the chamber, the Ashen Wolves had been freed from their bonds. All around there were corpses of Aelfric's followers, most having been killed by what was clearly the Rite of Rising gone wrong. Aelfric himself was nowhere to be seen. Far in the back, they could see Byleth strapped to a crucifix. She was untouched by the rampaging ritual, but she was also unconscious.
In the center of the Holy Mausoleum was a large crimson cocoon, disturbingly alike the one that Miklan had been in during his transformation into a Black Beast. Along the surface of the cocoon looked to be veins that pulsated as more blood was introduced to it. Several red tentacles were extending from it, skewering several of the bodies of Aelfric's followers and draining them of their blood.
The very sight of it caused Bernadetta to instantly faint. Fortunately, she was caught by Ignatz and dragged back to safety.
"What the hell is that thing?" said Leonie.
Hearing Leonie's voice, Balthus turned to the students and said, "Hey, could use a hand here, guys!"
The King of Grappling was bound by several tendrils around his arms and legs, and he struggled hard to break free. One of the tendrils had impaled his leg and was draining his blood from it. Meanwhile, Yuri was trying to pull one out of his left arm but was forced to slash through several more that lashed out at him.
Constance let out a shrill scream as several of the tentacles wrapped themselves around her waist, arms, and legs, her high-waist skirt torn apart to expose her legs. She made another yelp as one of them ended up coiling tightly around her right breast, squeezing it before sinking its tip into her chest, and her cries of embarrassment turned to those of pain as it began sucking out more of her blood.
"COCO!" Hapi screamed.
The redhead was about to fire a Miasma Δ spell at the tentacles when another lashed out and wrapped itself around Hapi's neck, choking her as it raised her off the ground. She too had a tendril skewer her a second later, this one choosing to stab her in the left side of her waist.
Flayn was the first to act, shouting out, "Help me Rescue them!"
The green-haired cleric began readying her spell, prompting Mercedes, Linhardt and Marianne to channel their Mana to her. Flayn's spell was ready within moments, surrounding the Ashen Wolves in white light before making them vanish. The Wolves reappeared before the students, with each one groaning in pain as Hapi coughed loudly and held her neck. But to the dismay of the students, Byleth had not been warped alongside them. Thankfully, the cocoon's tendrils seemed to be slowing their movement, and did not lash out toward the students. Mercedes, Linhardt and Marianne immediately went about healing the Ashen Wolves of their wounds.
"P-Perfect timing, you guys," said Yuri as he staggered to his feet. He then looked at Dorothea as he said, "Glad to see you got the message, songbi–"
Yuri was cut off as Dorothea slapped him as hard as she could.
"Look at what you've done, you scoundrel!" Dorothea snapped.
"Ow… Guess I deserved that…"
"Hey, leave some of him for us, Dorothea," said Balthus as he rose to his feet. "Yuri's got a lot to answer for."
"Agreed!" hissed Constance. "I am thoroughly incensed by his treachery!"
"Goes for me too," Hapi wheezed as Linhardt continued healing her.
"You'd better have a good reason for all of this, Yuri," Anna said crossly.
"Had no choice," said Yuri. "Aelfric was threatening people I care for. My mother, those in Abyss, and so forth. If I didn't help him with his plan, he'd have killed them all. Couldn't tell anyone about it either." Yuri then looked back at the red cocoon and said, "And now look what it's got him."
"Wait a second, that THING is Aelfric?!" Lysithea said in surprise.
"He started the ritual too early. Got scared once he realized I was trying to derail his plans."
"Wait, weren't you helping him?" asked Ingrid.
"I've been working for Lady Rhea for a while now, even before I met Aelfric. She knew he was up to something and had me report in on his activities. I had to make sure I didn't tip him off, so…"
"You played the role of a double-agent," said Lorenz.
"You know, you could've trusted us," said Sylvain. "We could've helped you out."
"I hate to break up the confession, but we've got bigger problems right now," said Claude. "Teach is still over there and whatever that thing is, it's getting bigger."
"Flayn, why did you not warp her to us?" asked Dimitri.
"I'm sorry, but something is binding her to that spot," said Flayn. "Likely whatever spell is keeping her safe from that cocoon."
"That'd be Aelfric's handiwork," said Yuri. "He knew Professor Eisner could get in his way, so he took her when he got his hands on the chalice. But he didn't want her to be harmed either, as far as I could tell."
"Why would he do that?" asked Mercedes.
Edelgard then asked, "Yuri, who is it Aelfric was trying to resurrect?"
It was at this moment that the group heard several tearing sounds coming from the cocoon. The tendrils writhed as they were drawn back into the cocoon.
"That doesn't sound good," said Anna as she drew her Levin Sword. The others readied themselves as well.
The cocoon started to burst open. A massive front claw came first, followed by a wing with exposed bone and sinew. A long reptilian tail followed suit, with large pulsating red veins strewn across its surface.
Finally, the cocoon exploded, sending torrents of blood in all directions.
"SITRIIIIIIII!" cried the Umbral Beast.
The students were petrified by the sight of the monster that had once been Aelfric Dahlman. It was massive, more than twice the size the Black Beast had been. Its body looked as though something had ripped off all its skin, exposing its muscle and bone. Large red pulsating veins were strewn across its body. A large red mane of hair surrounded its head, which for a moment bore Aelfric's face, albeit a horribly mutilated effigy of the old monk's countenance.
The Umbral Beast turned toward the students and immediately saw Jeralt, who grimaced at the sight of his old friend turned into a monster.
"YOU WILL NOT TAKE HER FROM ME!" the Umbral Beast bellowed.
Then, in a sight that made the students want to vomit, the flesh of Aelfric's face seemed to melt, revealing a horned grey skull beneath. Then, the sinew around what would've been the beast's chest began to shift and warp as something came out of it. It was the body of a woman, pristine in her beauty with long green hair, yet she looked lifeless as a doll. The woman's body was held in place to the Umbral Beast's chest by its twisted form.
Jeralt's expression immediately filled with sorrow as he said, "Sitri…"
"Sitri?" Dorothea said aloud. "Wait, isn't that… Professor Byleth's mother?!"
"Yes, it's her." Jeralt's expression and tone turned grim as he said, "Aelfric, what have you done?"
"You mean to say that Aelfric was attempting to resurrect your wife, Sir Jeralt?" asked Dimitri.
"How deplorable," said Ferdinand. "Did he intend to take her for himself?"
"Hey, guys, it's doing something!" said Hapi.
Indeed, the veins lining the Umbral Beast began to swell and bubble with blood, releasing several bloody orbs that hit the floor of the Holy Mausoleum. The orbs began to reform, taking human shapes as they coalesced into bloody effigies of both Aelfric and Sitri.
"By the Goddess…" said Constance in a tone of fear.
"Flame Spirit, protect us," said Petra.
The Umbral Beast let out another roar, sending the blood clones forward to attack the students.
"Captain Jeralt, what do we do?!" Leonie said as she readied her lance.
Dorothea looked to the Blade Breaker apprehensively, knowing he had to be taking what they were seeing worse than the others.
Jeralt tightened his grip on his lance as he said, "Take them down. They aren't really Aelfric or Sitri. Don't hold back against them. Anna, take Dorothea and get Byleth. Leonie, Edelgard, Dimitri, and Claude, you're with me."
The Blade Breaker then let out a battle cry as he rushed forward and, despite his remorse, lunged through the heart of one of the Sitri clones. The clone emotionlessly shuddered for a moment before it disintegrated into a pool of blood.
The students followed suit, rushing out to meet the blood clones, which began attacking them with either White Magic or Anima spells.
Before she could go after Jeralt, Edelgard made a brief yelp as Anna slipped up to her and snatched the Sword of the Creator from Edelgard's right hand.
"Huh?! Wait, Anna!" Edelgard said in surprise. "You mustn't–"
"Don't worry, Edelgard, I'm not gonna turn into a monster like Aelfric did," said Anna. The redhead then said, "Dorothea, follow me!"
Dorothea gave an affirmative nod as she ran behind Anna, who slashed through a clone of Aelfric with her Levin Sword.
Edelgard was briefly surprised. The Sword of the Creator had not reacted negatively toward the merchant. Did that mean Anna had a Crest?
"Lady Edelgard!" shouted Hubert, alerting her to one of the Aelfric clones about to throw a fireball at her.
Edelgard, cursing herself for being distracted, dove away from the attack just in time. She then rushed at the clone of Aelfric and let out a shout as she buried her axe in the clone's brain. The clone broke apart into a bloody pool as it was destroyed.
On the left side, Felix let out a loud shout as he beheaded one of the Sitri clones. As he slashed away a splash of blood from his sword, he turned to look at the Umbral Beast. To his and the others' dismay, more balls of blood burst from its body, creating more clones.
"It's making more of them!" shouted Hilda. "Ugh, could this thing be any more of a pain?!"
"Just keep taking them down!" shouted Sylvain as he struck down another clone with the Lance of Ruin.
"If we don't stop that thing, they'll never stop coming!" said Raphael as he punched down another clone.
As the students fought with the clones, Jeralt and Leonie rushed in toward the Umbral Beast. Leonie's eagerness led her to attack first, stabbing the Umbral Beast in its front left leg, but the strike had little effect. Surprised, Leonie made a loud yelp as the Umbral Beast swung its leg forward, sending her flying back. Jeralt caught her as she slammed into him.
"Don't be reckless, Leonie!" said Jeralt. "We don't know what this thing's capable of, so take it slow and careful."
"R-Right, Captain Jeralt," Leonie said bashfully.
An arrow from Claude struck the Umbral Beast's neck, doing little to harm it. Dimitri made another attack with his lance, and again the blow did minimal damage. The Umbral Beast retaliated as several new red tendrils burst from its body and attempted to stab Dimitri, but the prince was able to avoid the attack and skillfully slashed through the tendrils with his lance.
As the others battled the Umbral Beast and its minions, Anna and Dorothea rushed up to Byleth, who was still unconscious. But as they reached her, the bluette suddenly began to stir.
"Professor?" Dorothea said in concern. "Professor Byleth, are you alright?"
Anna went to work unlocking Byleth's restraints as the bluette's eyes fluttered open. She immediately saw the two before her.
"D-Dorothea? Anna?" Byleth moaned.
Still woozy, Byleth had to wait for Anna to release her bindings as she looked over at the battlefield, her vision not yet focused. As she watched the others through blurry eyes, she thought she saw something like red snakes slithering through the air.
Too late, she realized what was coming, and before she could shout out a warning, several of the Umbral Beast's tentacles had speared Anna through the back.
"ANNA!" Dorothea screamed in horror.
The look of shock on Anna's face froze as time ground to a halt.
"What in the world is that thing?!" said Sothis. "Whatever it is, it is clear we must stop it, and we cannot have Miss Anna dying at this point!"
Byleth could only wind back a short distance. The tendrils darted back through the air toward the Umbral Beast. Byleth's arms were forced back into her restraints.
The flow of time resumed its flow, and once again Byleth's vision and mind were a blur. But at least this time she knew what was coming.
Byleth looked up through her blurred eyes to see the red tendrils readying themselves to strike Anna.
"Look out!" Byleth shouted in alarm.
Dorothea was the one to react first, turning to see the red tendrils poised to strike at them. Immediately the singer raised a hasty ward to counter the attack, as Anna was too focused on freeing Byleth from her restraints. As the tendrils slammed into the ward, Dorothea let out a shriek as the ward shattered instantly, though it was enough to stop them from hitting Anna.
Then, Byleth's blood turned cold as she saw the tendrils suddenly writhe before swiftly wrapping themselves around Dorothea's body.
"AH! Let go! Let – AAAAAAHHHHHHH!"
Dorothea let out an earsplitting scream of terror as the tendrils suddenly pulled back, lifting her off her feet and making her drop Joyeuse as she was sent careening into the body of the Umbral Beast. Upon colliding with the monster's body, Dorothea suddenly felt something that filled her with utter panic.
It was drawing her into its body.
"No! NO! NOO! HELP! HELP ME!"
Dorothea continued to scream for help as more tendrils began wrapping around her, her left arm outstretched to try and escape, desperately hoping someone would pull her free. But to her despair, she continued to be pulled deeper into the Umbral Beast's body.
She let out one last scream of terror before the Umbral Beast wrapped its tentacles around her left arm and she was pulled completely into its body.
Damn me and my cliffhangers, right?
I chose to have Aelfric turn into the Umbral Beast earlier than in the DLC because of Jeralt's presence. Having him see Sitri's body in pristine condition before the ritual was done would've been very hard to write, as he'd have learned things too early from Rhea (which in turn would've led to Byleth learning too much too early).
Also, just so you know, I'm having the Umbral Beast's whole "spatial-distortion" attack removed in favor of its tentacle-based attacks. And though tentacles are my favorite hentai niche, I don't plan on being too raunchy at any point in this fight (Constance got it enough). I also added in the Umbral Beast creating Sitri clones as a way to make the battle feel darker. Sorta gave it a SMT: Persona 4 vibe.
And as for what will happen to Dorothea? Well, you'll find out next chapter.