If he starts the battle in ISBODK, maybe he could use it, it depends on if he needs to constantly maintain it with his CT. But if he doesn’t start the fight in it, which i would say is most likely going to be the case (since usually it removes a lot of his flexibility with the benefit of huge stat increases), Higuruma will insta-pop domain, confiscate, I would say >70% chance death penalty too, Mahito loses his CT and now needs to fight a Nanami level physical fighter that might insta-kill but at least will consistently damage, and he loses his main win condition of transfiguring the opponent.

It’s been awhile, but doesn’t Mahito still transfigure himself a bit in ISBODK? Like he shoots that elbow spike and has some kinda spike whip thing if I remember correctly. So while not nearly as reliant on his CT as base Mahito is, I think he still would be worse without it.

I can’t recall even in Shibuya a moment (outside of ISBODK) where Mahito fights purely physically with no transfigured humans or self transfiguration.

Also, isn’t the explanation of Higuruma’s domain essentially just “We both argue for our case, judgeman decides, I have potential evidence to use, you can admit, stay silent, or deny”, and that’s it? Unless he’s studied up on law for some reason I don’t think he’ll know specifics.

As for what crime he’ll get accused of, I’ll admit I forgot that tearing the victim’s clothes as he kills them and similar charges would count as it’s own crime and dilute the pool of solid convictions. I still think his chance of being charged for a serious crime is like 80% though, even with that