If you like One Piece, I would highly recommend Dungeon Meshi. It has great worldbuilding like OP, just on a much shorter scale (less than 100 chapters, but some of the best chapters you'll read)
It's always weirded me out when people say protagonists have to be boring blank slates. If I was following a character for an entire story, I'd at least make an attempt to make them interesting
Not as terrible as I was expecting, but he should look more "gremlin-y" for my taste This guy looks like he'd be scared of the vacuum. The actual Loki got pregnant from a horse.