The idea was that Tomi kidnaps Hifumi's sisters and forces him to choose which one to save, to make him feel powerless.
Not 100% sure about the setup, but I imagined it as something like he's streaming him the footage of them from three distant locations, with little enough data that he knows it will take Hifumi a long time to get there, and he has some way to quickly dispose of them (kill, change the room enough so he can't teleport there, or they are being driven out of his range) (it requires Tomi to have studied Hifumi quite well to know his limits like that, reflecting the nemesis status). So when Hifumi gets there, and saves one, the others are supposed to get out of his reach, either with some automatic trap, or just order to henchmen etc. Possibly, Tomi also gives Hifumi an option to go after him instead of trying to save his sisters.
After the fallout of the Trigger use, Hifumi sees the fact that he used it back then as the fact he had given up, and refuses to do that again; refuses to compromise. He declares that he will save them all (AND take Tomi down).
That's when he Awakens and the multilocation kicks in, with him getting to all his sisters (and Tomi) at the same time to save them (and beat Tomi).

I don't think like it quite works, tho, and I feel like if I tried to write that, I'd just end up rotting again. I think I need some other way to wrap up the Tomi situation. Maybe just a mention in the next bonus that the blow from having so many of his henchmen and the construct beaten, was enough that Tomi lost his position and/or got captured by the police and/or Heroes?

As for the possible Awakening itself, I think it will still be a situation where he has to save multiple people at the same time, but in different, less asspully conditions. Maybe during a battle with Sandy? Trigger side effect that builds into that would be developing some pathways in his brain that help him handle overlapping mental images, but possibly also some damage that builds into how extra strenous the use of it would be.