Katsuki always suspected Deku held back in sparring matches, but now he had proof.
He hit the concrete after Deku got hold of his arm and threw him across the room with enough force to slam him into the floor. He was lucky his ribs hadn’t broken. Katsuki would have used his Quirk to stop the fall, but he still hadn’t caught his breath from the knee to his gut that came immediately before the toss.
On impact, he rolled into one of the metal conveyor belts, slamming his back into it. Katsuki heard a rip as sat up and twisted to unlatch the fabric of his shirt from the stray hook it’d caught on.
“You little shit,” Katsuki hissed under his breath. Alpha got a heck of a strength boost when they hit this point, but Katsuki wasn’t a pushover. He went head to head with Deku and his stupid One for All Quirk and held his ground just fine! The extra adrenaline and steroids shouldn't have made that much of a difference, so the brat must have held back before. “That fucking hurt.”
“Then stay down,” Deku said. He turned back toward the hole in the wall, returning to his original target.
“Oh, no you don’t,” Katsuki said, launching himself up and across the room. He spun into a kick and slammed his leg into Deku’s waiting block, pushing him back. “We’re not done!”
He followed with a large burst of explosives aimed straight at Deku when he moved his arms. Maybe if Katsuki hit him enough times, he’d snap out of it. Deku seemed to be holding onto to some semblance of sanity beneath all the Alpha instincts so a little push in the right direction might be all that idiot needed. At least one of their conversations had to break through.
Katsuki hit the ground on his feet and threw his hands forward to keep up the barrage of hits.
When he stopped to take a breath—two weeks off really put him out of shape—he faced a highly unamused Alpha, lowering his arms away from his face. Deku’s Quirk continued to spark and he looked more or less unharmed.
“I really hate your Quirk some days,” Katsuki said under his breath.
“Are you done?” Deku asked, eyes still blank but Katsuki could feel them staring right at him. He shifted his foot back, getting back into an offensive position. “Because I’ll—”
Deku stopped, head tilted down.
Katsuki followed his line of sight until he saw what caught Deku’s attention: His torn shirt revealed his shoulder.
And the new Mark.
“That explains how you moved earlier,” Deku growled, fists tightening further. His specialized gloves cracked at the knuckles. “But it doesn’t explain why you keep getting in the way.”
“Someone’s got to calm your ass down,” Katsuki said, breathing hard. He couldn't ignore the internal voice laughing that this might be the most willing Omega-like thing he’d ever done in his life. It kinda pissed him off. “So if you want me out of the way, you better start hitting harder.”
Deku's breath shuddered, head flicking to stare at the Mark before going back to Katsuki’s face. He hissed, “Why are you protecting him?”
Because Deku would hate himself tomorrow if he knew he murdered people while all his inhibitions were compromised.
Because Dabi would be upset if something happened to that shit Alpha of his.
Because Katsuki was really sick of sitting on the sidelines and saving people was what he did.
“It’s my job,” Katsuki said, “in case you forgot.”
“You’re strong, Kacchan,” Deku said, leaning forward. His fingers twitched and his breath increased. That small grip on his sanity continued to slip away—the opposite of what Katsuki had been trying to achieve. Deku growled, dropping into a sprint. “So if you really want me to make you submit the hard way, so be it!”
“Shit.” Katsuki used his Quirk to throw himself out of the way in time, barely missing the Detroit Smash that landed where he’d been—taking a literal chunk out of the floor. Defense became the game as Deku’s speed picked up and it occurred to him he might be in over his head. “Are you trying to kill me?”
“No,” Deku snarled. He moved an inch faster, tackling Katsuki in the side. They rolled until Deku had him pinned, face in the ground and sitting on his back. “I’m trying to kill all those other Alpha that keep touching you!”
Katsuki winced, feeling the strain on his arm as Deku kept it twisted behind his back. Any more pressure and his bone would snap. He winced as his previously friction burned cheek scraped the ground once again. “Insecure, much?”
“Don’t act like I’m stupid, Kacchan. I know I’ve never been your first choice for a mate. I haven’t even been your second or third,” Deku said, breath still heaving. He leaned forward dropping his forehead onto the nape of Katsuki’s neck. “But when I’m done, I’ll be your only choice.”
From the sidelines, Dabi watched Midoriya stand up from Bakugou’s back and kick his Omega so hard in the side that Bakugou howled, curling in on himself on the ground. The Alpha left him there and turned, eyes still black as night and locked on the opening in the wall where he’d first been thrown through and been trying to return to since the fight started.
He clearly had his sights set on one goal.
“We need to leave.” Dabi tugged on Shigaraki’s sleeve, aware his hands were trembling but he felt freaking justified with that—that thing masquerading an Alpha in the other room. “Where the hell is Kurogiri?”
“If he has any sense, far away from here,” Shigaraki said, that fucking smile still plastered across his face. They were going to die and he looked as delighted as a little kid. “And if you think we can outrun him, you’re not as smart as I thought you were.”
“Then what are we going to do?” Dabi asked, eyes on the Alpha slowly approaching them. He didn’t look to be in any hurry, stepping around the broken machinery and rubble he’d created with his fight with Bakugou. “Because my fire’s strong but it’s not that strong.”
Shigaraki dropped his smile and tilted his head toward Dabi. “If you’re scared, just stay behind me. We’re going to be fine.”
Midoriya continued his steady approach, his pace quickening as he noticed Shigaraki and Dabi standing in the broken wall.
“How can you believe that right now?” Dabi asked, fingers twisting in the back of his Alpha’s shirt. “He’s going to murder us. Bakugou warned us about this and we brushed him off and we’re—”
“We aren’t going to die,” Shigaraki said.
Midoriya ran toward them fist raised and crying out, “Shigaraki!”
Dabi readied his Quirk for a last ditch effort and—
Bakugou slammed into Midoriya's side, an explosion behind him. The force flung both of them sideways, smashing into the outside wall of the building. They broke through and crashed into the street, rolling to a stop in the center of the road.
“You should have a little more faith in that new toy of yours,” Shigaraki said, stepping into the warehouse. He walked away from the fight toward a stairwell on the far side of the building. “We’ll be able to watch them better from the roof.”
Dabi swallowed, sending Bakugou a silent prayer as he followed after Shigaraki.
Everything hurt, but Katsuki kept punching. He’d caught Deku off guard for a split second and he intended to use every inch. Each hit returned a new snarl, the last dredges of Deku’s sanity long gone. He backhanded Deku across the cheek and screamed, “Wake up already!”
His upper hand didn’t last. Deku squirmed enough that he could get his leg up and he kicked hard, throwing Katsuki across the street and into the neighboring building. Instead of going after Shigaraki again, Deku seemed set on making sure Katsuki stayed down this time. He sprinted forward, kicking Katsuki in the side before throwing a punch.
The next hit threw Katsuki into a street lamp. He managed to catch his balance and used it as a jumping point to throw himself back at Deku with a new explosion at the ready. “What’s it going to take to snap you out of this?”
Deku dodged his hit and growled back at him like a wild dog.
Each of his moves turned more and more animalistic as he dodged and ran at Katsuki, using his arms more as he pushed off nearby surfaces and continued his assault.
“Fucking look at you,” Katsuki said, wincing after Deku got in another clean hit. Katsuki screamed back, catching Deku’s arm and throwing him over his shoulder. He managed to get a good toss in and slammed his palm into Deku’s back. He let loose an explosion straight into his back and Deku screamed. “You’re supposed to be better than this!”
Deku ducked down, tripping Katsuki over his shoulder and getting back up to keep going.
He didn’t even look out of breath.
“Shigaraki was right—You are the scariest monster around right now and for what?” Katsuki’s voice cracked as swung his fist. Deku caught it again, twisting until he caught Katsuki’s arm in a hold. Katsuki smacked Deku’s bicep, feeling his energy leave him and he dropped his head. “Me? You’d murder someone in cold blood for me? You’re the number one Pro Hero and you’re going to throw everything away! I’m not worth it, you idiot!”
Deku stilled. Only his grip trembled around Katsuki’s trapped hand. Deku sucked in a breath and exhaled, voice thick and sore. “Kacchan.”
He blinked and Katsuki nearly fell to his knees in relief when he saw the green return to his iris. Katsuki mumbled, “About time—”
The world went black.
“This is Shouto,” Todoroki said into his communicator. “The situation has been contained.”
Eijirou stood by Todoroki’s side and stared at his best friend locked in ice with Midoriya. He focused on keeping his breathing controlled.
After Todoroki’s all-clear, police and the rest of the containment team entered the area to collect Bakugou and Midoriya for questioning.