In Hawk Moth's lair...

"Ah, bullies. The kind of guy to rule the student body with an iron fist. It seems he's failing at his job due to that octopus-like creature for a teacher," the large circular window opens, signalling it's time for him to make his move to create another supervillain. "How perfect this is."

He extends his left hand to let a single white butterfly fly to it and covers it with his right hand, filling it with dark energy. This process converts a butterfly into an akuma.

"Fly away, my little akuma, and evilize him," he ordered the empowered creature to fly away and seek his chosen victim.

The akuma approaches Terasaka, causing a moth-shaped emblem to appear on his face.

"Browbeater, I am Hawk Moth. Your octopus-like teacher has taken everything away from you," Hawk Moth spoke through him. "Lucky for you, I'm here to give you the power to strike back and regain what you've lost. Just be sure you bring me the Miraculous in return if you have the brains to figure out what that is. Is that a deal?"

"You got yourself a deal, Mr. Hawk Moth!" Terasaka grinned at the offer he's given.

As a result, black and purple smog covers his entire body and when it's all done, his appearance changed. His hair is now red, his skin is now pale, and he now wears a black bodysuit with gauntlets on his hands.

He is now Browbeater.

"Guess I won't be needed on this one," Shiro commented on seeing what just happened with Itona by his side.