The fact that this series has some of the best fight choreography and art I have ever seen and been at the same time UNBELIVABLY HORNI... never ceases to impress me.
I hope that Hamada-sensei really expands on this Soul Shrine thing, I mean really COMMIT to it.
I am not particularly sore with new powers being introduced, when they have at least some connection to the system already defined, but... I won't lie, this has too much similarity with Domain Expansion XD (not that the concept was created by JJK, it wasn't).
But do think that Hamada-sensei really needs to show how this technique will play as time goes on, even if they are something only those with a true grasp of their power can do, there shouldn't be a shortage of those.
And as they seem more utilitarian than "explode everything" abilities, the rules of each one will need some thinking, this fucker is a creep among creeps, but his Shrine makes sense in the context of his desires and even being simple the rules can clearly be used in smart ways.
But a funny thought... I think it would be interesting if Kazuya is unable to use it, I know it sounds strange, but I feel that he is just... too overpowered now, he catches concepts too quickly, even if this is the type of technique that needs to be used smartly and can backfire, I would prefer if he isn't able to use it and focus on his martial arts, simple barriers and using his tsukumogamis in combos, he is a character with an already big arsenal of choices giving him this one would feel too much, at least for me.