Raiju is just going to slow down APM I think. I think it's for sure a thing that other weaponskills will cancel Raiju combo. Might get lucky and be able to weave in Mudras. Otherwise weaving oGCDs is a must during Raiju.

Mudras are abilities and not WS's so that might be plausible.

It's looking like Raiju combo will require Bhavacakra weaves or oGCDS. And the Bunshin finisher is a Weaponskill too so that will cancel Raiju.

But Raiju is always available every Raiton at 90 so this is going to throw a wrench into Ninja rotations.

Don't see the purpose of Hiraijin. Will probably be Ninja version of Anatman.