User is Atsushi.

Dazai watches, letting out an exaggerated sigh. Atsushi, the 'were-tiger', had lost control of his ability again, resulting in a massive white tiger causing chaos.

Dazai smiles, trodding over to the tiger, watching it as it aggressively snarls at him. He pats it head.

In a matter of seconds, the tiger had formed into a boy again, and he smiled down at Atsushi.

"Good thing we have my nullifying ability, huh?"