"Wouldn't dream of it," Akira makes a "crossing his heart" gesture. "If I do fuck up Crossroads, I won't dodge your knife next time."

As for that second part...he smirks. "It's something like that," he answers. "See you later, kouhai."

In the blink of an eye, he becomes something wrong-terrifying-monstrous-nononono, and then becomes a puddle of magnetic goo, falling up into the ceiling of Mementos. Then, he's gone, like a bad dream fading in the light of day.