I used this chance to test Nobukatsu in a CQ with Avenger Nobu, and I'm quite pleased with the result, it honestly went better than I expected.
I'm definitely raising his skills to 10 and giving him one grail in the future so he has more HP because he was really close to die without using his NP, but I want to wait for next event to get a bit more Crystallized Lore, as my supplies are still low and I don't want to suddenly find myself in need of them.