SlimeSage
This was not what I meant when I said 'The shrek part was boring', I was so hyped up for hotel transylvania part that it seemed filler to me ALSO the main reason that this ff is amazing for me is not it's fights but the plot and worlds that are never used in any ff before or not in any good ff before. So if the OC reincarnator part is just for power fights then it's a bad desicion instead you could make the OC a typical webnovel MC(braindead), add some comedy and some plot. For fight scene make a large plot buildup before JIN squashes him like a fly. And for a real challenge for jin I would recommend the idea of BattleKing10000 an organization would be better. Well all of this is a suggestion you can do whatever you want I'll be reading it. I only drop ff's when 1.it's ntr 2.reading it becomes a chore.
Personally, I think a faction would be better instead of one powerful enemy because it's literally in his job description to combat threats like these. If you want spice then you'll never run out because who knows how old and powerful an organization formed to overthrow God or conquer worlds in the omniverse would be. This way you can keep from writing yourself in a box if your Oc reincarnated Antag. doesn't go how you plan it to.
Are those reincarnator will be the main enemy of Jin only at hotel Transylvania or it'll be his main enemy in this story? I mean following him to another world too, like keep hunting him down for revenge or something...... Well I'll just wait and see how things turn out...... But without OC Reincarnator you still have OC God right? Isn't Jin jobs is to take care a world that's became mess up because of those weird God? Hmmm....... Well we'll see it then ( ´・ω・)