Yeah, I think I found Mori most likeable and appealing when he was at his least powerful

I can see that. Fwiw, he spends a lot of the second novel depowered. It's also a pretty hurty novel, in terms of hurt/comfort -- idk if that's relevant to you or not, but it's significant enough to be worth saying, I think.

Hence Phineas Fletcher.

I'm sorry, I don't know/remember who Phineas Fletcher is?