Izuku's Quirk idea came from the same place as this whole fic storyline (with minor changes bc I'm a villain tododeku shipper and I couldn't resist) and I don't think Katsuki wouldn't be saved:

'Burned~BNHA Villain Deku animatic' by Strawberri Draws

"Kacchan, you can't save me. I know you want to, but it's not possible if I don't want to be saved." the green-haired boy said, not turning around.

"Deku." Katsuki panted out. "You fucking nerd, don't you dare turn your back on me!"

He launched himself towards his former friend, extending a hand forward in preparation for an explosion to knock Deku down a peg.

But instead of meeting flesh and cloth, his extended hand connected against a smooth green barrier, the explosion doing nothing but bouncing him back.

He landed roughly against the packed dirt, and sat up just in time to see Deku point a finger at him, some of the same material the barrier had been made of collecting at it's tip.

A beam shot from Deku's finger, and Katsuki braced for pain, but when he opened his eyes he was just encased into a similar green bubble as Deku had been.

He watched as three of his classmates landed into the same clearing as Deku and him. Uraraka, Todoroki, and Shoji had arrived. He crawled to the farthest edge of the circle and pounded on it, and could only watch in horror as Todoroki was encased in another bubble.

Shoji tried to attack Deku, but was rebuffed just as Katsuki was. He saw Deku speak into something, and tried to warn his classmates, but it looked like they couldn't hear him.

They yelled to him, but he couldn't hear them either, and his vision was suddenly swallowed by an expanse of what seemed to be pure space, what he remembered to be the warp fucker's 'gates', from USJ. That meant that all those stupid fucks who'd attacked them were from Handjob's crew. Made sense.

He re-emerged from the inky expanse in a gross bar, very obviously rundown. A blonde girl came up to his bubble, and stuck something into it, and his vision began to swim. He fought it as best he could, but the dizziness soon overtook him, and the last thing he saw was Deku's mocking smile.

He became aware in pieces.

He could first identify the taste of blood on his tongue, though from where he couldn't identify. The ringing in his ears became clear next, and when he tried to bring his hand to his head to rub it away, he couldn't move them, and so he opened his eyes blearily, and through the blur he could make out several colored shapes, the closest of which was green.

Blinking rapidly, he brought the room around him into focus, and was met with the sight of Deku, standing next to several others; there was the blonde girl who'd knocked him out, the crispy fucker, Handjob, with the stupid hand still over his face, and the warp gate. Behind Deku he could somewhat see Half-n-Half next to crispy fucker, still conked out with some kind of bracelet on his wrists and rope tying him to the chair he was on.

He tried to call out to Half-n-Half, but it was muffled, and only then did he realize he was muzzled like some kind of rabid dog.

"Ah, he's awake." Deku said, walking over and grabbing the muzzle on his face, standing off to the side. "Shigaraki, I'm warning you, he's got a bit of a bad mouth."

The muzzle was pulled off his face. He sighed, and stared at Bad-Touch as he asked roughly, "What do you fucks want me for?"

"Wow, such a potty mouth. You're right, Kingpin, he's not that impressive in person, much less aggressive." Bad-Touch drawled, spinning around in his stool to face Katsuki. He smirked from behind his hand-mask, and Katsuki just glared in return.

"You didn't answer my question." Katsuki repeated, hiding his panic and anger to try to assess the situation. "Why am I here?"

Deku ducked into his immediate line of sight. "Shigaraki thinks we can persuade you to join us. I think he's nuts."

Katsuki huffed. "Why, exactly, would I join you, you bunch of fucking retards?"

"You could be number one. Show everyone in class 1A that you're better than them." Bad-Touch offered. Deku just stood off to the side, rolling his eyes.

"I already do that, fucker. Anything else?" he asked, glancing out the window and seeing a blur of red, white, blue, and yellow.

Deku narrowed his eyes, walking over to crispy fuck and whispering into his ear. Crisper just nodded, and easily hefted Half-n-Half up, chair and all, and took him in the back, with Deku following close behind.

Just as the door swung shut, two things happened at once.

Katsuki blew off his restraints.

And the symbol of peace blew through the wall, shattering glass over the villains and causing most of them to scatter.

Blondie managed to make it into the back, but the rest were caught by Kamui Woods, immobilized.

Bad-Touch disintegrated his binds in just a couple of seconds and lunged towards All Might, but became limp as Nighteye immobilized him a second time.

Katsuki tried to tell All Might that Deku- Kingpin had taken Half-n-Half to the back, but before he got a word in, his throat was clogged with a viscous green sludge that bubbled out of his mouth. He choked on it, but it just kept coming, and he was engulfed in it just as All Might reached for him.

He re-emerged in what seemed to be a desecrated wasteland, surrounded by Hand-man, Two-Face, the lizard guy, and an unconscious warp gate.

He spat out the last of the gunk in his mouth, and gave a savage grin, baring his open palms. "This'll be fun."

He lunged for Two-Face, catching the guy in the face and setting off an explosion right when he hit contact, launching him off towards Godzilla across the way, and he managed to get that guy in a triangle chokehold, bringing the guy down but simultaneously letting Two-Face get back up. He used Lizard as a stabilizer, and set off a controlled blast Handjob's way, causing the guy's hand mask to fall off his face.

That appeared to be the wrong move, as all it did was get Bad Touch angry. "I'll kill you for hurting Father!" the guy yelled, and the seriousness in his voice and the wildness of his gaze sent a shiver down Katsuki's spine.

Ignoring Handyman for a second, he shot a thinner and stronger blast to Two-Face's chest, knocking the guy out. Handyman didn't like that, and began to shout and scream about life being unfair like the whiny baby he is.

Katsuki's back finally met the packed dirt as Lizardman passed out, and he released his chokehold, only for an engine to rev and Zoom and Kirishima to speed by him, with Kirishima's hand outstretched.

"Come on, we gotta go!" Kirishima yelled, and Katsuki grabbed his hand without hesitation.