He's quite successful! And another person arrives!

Izuku watched and kept trying to move, as Todoroki started trying to blast Stain with fire and freeze him with ice. His use of both sides of his Quirk was carefully controlled, but Stain was quick and experienced, dodging every attack.

He ended up throwing his combat knife, cutting Todoroki's left cheek. He then managed to get close to Todoroki, trying to lick his cheek directly with his long tongue. Todoroki however immediately fended him off by producing flames, and **** Stain to retreat. It seemed like a stalemate mostly, but Stain decided to get a little more rough with incapacitating Todoroki, throwing more knives, getting him in the arm.

Izuku then felt one of his fingers move, and his eyes widened as sensation returned to his body. Todoroki naturally put out more ice, but Stain closed in again, this time aiming to cut his tendons. "You're far too reliant on your Quirk!" he lectured Todoroki, before swinging. His blade would have bitten into Todoroki's arm, but Izuku, clearing the ice wall, slammed into Stain, carrying him off and slamming him into said ice wall with a turn and throw.

Stain grunted. "...he must be Type O..." he thought, and momentarily considered just cutting his losses and running. He dismissed the idea. Killing Bakugo was too important to him. He was clearly their classmate. If he was allowed to live, that would be a vector for the rot of society to get to these two potential Heroes before him.

"How are you moving?" Todoroki asked.

"His Quirk wore off. There's likely a time limit... But if so, it should of worn off on Native and Kaa-chan first. I have a few ideas on why. It might have to do with the amount of blood he ingests. It could also get weaker the more people he uses it on... Or it could be because of blood type," Izuku analyzed.

Stain smirked, impressed as Native contributed from behind the ice wall, "If it's the last one, I'm Type B."

Bakugo clenched his teeth, still unable to move. "Not that it's any of your shitty business, but I'm Type A..." he reluctantly added.

"Midoriya, Bakugo, Todoroki!" they heard from the entrance of the alley, and Izuku and Todoroki turned their heads briefly to see Iida at the entrance of the alley. "I got your message! I apologize for the delay, but I stopped to call the police," Iida said, stepping beside them, fixing Stain with a hard glare. "Though I am unsure when they'll get here, given the situation with the Nomus... My brother is currently helping in the fight against them..."

"...I see... You must be the brother of that fake who I somehow failed to cripple," Stain sneered. "His armor must have redirected my blade slightly more than I thought," he reasoned. "So... You here for ****?"