I've cooked enough, i'm gonna drop this here in case it becomes true:
King Loki is gonna be One Piece's version of Utgard-Loki, a king of giants who uses cunning and magic against Thor and the God Loki.
Luffy, as Nika, will be seen as the actual God Loki by the end of the arc.
Usopp will be seen as Thor, for being able to use a fake "10 Ton Hammer".
Sanji will be seen as Baldur, the god that is immune to all damage and can regenerate anything.
Zoro will be seen as Hodr, god of darkness and winter, Baldur's brother. He is blind. In Norse myths, he is tricked by Loki into killing Baldur. So maybe Zoro vs Sanji shit happening in Elbaf? Hodr killing Baldur is the kickstart to Ragnarok.
Nami will be seen as Freya, goddess with elemental magic.
Robin will be seen as Hel, goddess of death, half dead girl, because of her Devil Form and being seen together with Brook.
Shanks is seen as Tyr, the merciful one handed god.
I'm gonna guess King Loki here is gonna be like Orochi in Wano, the actual villain will be One Piece's version of Odin. A one eyed pirate, with an eye patch, who is seeing everything happening here. Maybe he is the man marked by flames in one of his eyes being burnt and maybe he is the one waiting for the Straw Hats.