Idk, I still think Loki will just play his endgame role like Yamato, Carrot, Shirahoshi and any other sovereign/ally to Luffy outside of the Grand Fleet. He's definitely ruling Elbaf while Hadjrudeen stays in Luffy's fleet at least imo.
Plus Im not even sure how you scale him down to appropriate size and he also seems waaaaaay too strong to the point where yeah Zoro and Sanji might be above him eventaully but then I feel like he throws the rest of the crew way off power dynamic. Like before this it felt like Jinbe wasnt "too" far behind the monster trio. Add Loki and I feel like everyone has to eclipse Jinbe by several orders of magnitude.
I'd still want it to be Kuma, just given his backstory and relevance to the crew, but I think that ship has sailed already too.