I think I want to rename this fic. Feel free to suggest names.
"Well, that's not good," Shamir voiced the group's collective thoughts before the Hegemonic Beast attacked.
Edelgard's monstrous claw swiped towards Caspar. Fortunately, he was able to dodge the attack, and even hit the offending hand with his axe. The weapon merely bounced off of Edelgard's hand, doing no damage. "Well, shit."
"Thoron!" Dorothea blasted Edelgard with a lightning bolt. It didn't seem to be very effective.
"What even is that? I mean, I know it's Edelgard, but did she get turned into a Demonic Beast? Or something different?" Caspar asked.
Alois deflected a slash meant for Shamir with his shield, which held but was mangled badly. The ex-mercenary sent an arrow at the enormous husk, but the arrow simply bounced off her shell.
Another arrow that came from behind, however, seemed to be more effective, getting past the scales and actually sending Edelgard reeling. "I hit her!" Bernadetta exclaimed.
Edelgard didn't seem to be too hurt, though, and she turned towards Bernadetta and the two other boys. "Oh goddess, I hit her. You're in for it now, Bernie!"
"Lady Edelgard! Please, it's me, Hubert!" Hubert tried. If Edelgard recognized him, though, she showed no indication of it, instead slamming her gigantic hand down. Hubert only barely dodged the attack.
"Hubert!" Bernadetta shouted, firing several arrows at the Hegemon Husk without thinking. Again, they seemed to actually be effective.
The downside, however, was that Edelgard returned her attention to Bernadetta. To keep her from attacking her, Hubert launched a Banshee spell at Edelgard, but the look of anguish on his face would have tricked someone into thinking he had been hit by the spell himself. Meanwhile, Ferdinand attempted to attack with his lance, but the effects of the attack were negligible.
In order to distract Edelgard from attacking his students, Byleth lashed out with the Sword of the Creator, intentionally aiming to create a minor but noticeable wound. The gash he created was small, but the diversion worked; Edelgard was now focused on him.
"Relic weapons are effective against her," Seteth realized. "Jeritza, attack from the left. Catherine, attack from the right." He himself quickly circled around Edelgard, and attacked her with the Spear of Assal from behind. Byleth, meanwhile, struck again with the Sword of the Creator.
"Fight it, Edelgard! I know you would never allow yourself to be used like this!" Rhea shouted, attempting to strike the Hegemonic Beast with her sword, only for it to bounce off.
Edelgard made a horrible noise and charged at Byleth, but Flayn used Rescue to get him out of the way. Edelgard kept charging and slashed at Gilbert and Roger, tearing the former's Fortress Knight armor.
"Hey!" Alois shouted, charging and stabbing at the Hegemon Husk. "Leave my knights alone!" Gilbert and Roger also tried attacking Edelgard, and Shamir and Cyril tried shooting at her, but none of them did very much damage.
Dorothea used Sagittae to catch Edelgard's attention. "Please, don't make me hurt you, Edelgard!"
Edelgard ignored her plea and attacked, only for Rhea to toss aside her sword and punch her as hard as she could.
Edelgard's already-cracked "dress" portion of her insectoid exoskeleton shattered, and the unnaturally long limbs broke off only for new, shorter limbs to grow in their place. In addition, enormous dragonfly wings sprouted from her back, and she took flight.
"She can fly?" Caspar asked.
"That's her ace in the hole? It's not impressive," Shamir smirked, "We just have to take out the wings, and then we win." She fired several arrows, trying to do just that. Edelgard effortlessly dodged them all. "Okay, maybe I spoke too soon."
Edelgard flew toward Shamir and attempted to claw her apart, but before she could reach the ex-merc, draconic wings sprouted from Rhea's back and she attacked Edelgard. "This isn't you, Edelgard! Please, stop!"
The two of them rushed through the air, with Edelgard trying to sink her claws into Rhea, and Rhea using her shield to protect herself while striking out with her fist. After several seconds of this, Edelgard's claws got stuck within the shield, just for a moment.
In that moment, Rhea pulled her shield to the side, forcing Edelgard's clawed hands away from her center of mass. With Edelgard unable to protect herself, Rhea landed a punch that broke the remainder of Edelgard's exoskeleton. Edelgard fell to the ground, her inhuman features disappearing.
Rhea landed next to her, her wings vanishing. She knelt down and began healing Edelgard. "You cannot die here, Edelgard. I will not allow it!"
Edelgard couldn't swim, but if she imagined what simply drifting on the water would feel like, she expected it would feel much like what she was currently feeling. She idly wondered when had been the last time she had felt so peaceful. Maybe she never had. She could just stay like this, fade until she was gone...
A voice abruptly broke the feeling of pure immersion. "Do you wish to die?""Why not?" Edelgard thought. Fódlan didn't need her, Dimitri would rule well, she would just get in the way.
"Then answer this. Will you die as Thales's pawn?"
Edelgard's peaceful feeling evaporated instantly. "Not like this. Not like this not like this not like this..."
"Yes! Fight it! Live!"
Edelgard felt for a lifeline, and found one. With all her spiritual strength, she grabbed it.
"Not like this!" Edelgard shouted as her fading life returned to her body in full force.
Rhea, relieved, embraced her wordlessly. Edelgard hesitated for a few seconds before awkwardly hugging her back.
"Okay, I hate to interrupt the moment," Shamir said, "But what just happened? With the wings and shit?"
"I suppose you do require an explanation," Rhea agreed. "Not here, though."
"Tonight," Edelgard agreed. "We'll explain everything."