Gokudera told them so.

When Kaz explained the mission to her, he'd described a deep-sea fish whose scales could reverse the harmful, out of control magic that was razing the streets of Ketterdam. No one had expected to find this, a half-dead, half-Siren Shu floating in the depths of a ship.

“Give me an update, Nedzu,” Aizawa spits into his phone as he yanks the car door open, “What do we know?” “At around four o’clock today, the pro hero Hawks was doing an impromptu signing for fans when a member of the hate-group known as the Creature Rejection Clan pulled out a gun and shot into the crowd. Like any hero, Hawks took the bullet himself, rather than risk civilian injury.” “And how exactly did that lead him to kidnapping Tokoyami?” Or Hawks gets hit with Trigger and it brings out his bird instincts. Tokoyami is there for all of it.