Of all possible devil fruits, it might either be the Wolf/Fenrir fruit (since Fenrir is Loki’s son in myth, was tied up by chains by the Gods so that he doesn’t become a bigger threat, and eventually breaks free and kills Odin, the king, and causes the end of the world in Ragnarok)
It might also be the actual Paramecia version of the Gum Gum Fruit, as Loki calls himself the actual Sun God; the Elbaf Giants might’ve confused the Hito Hito No Mi: Nika to the Gum Gum Fruit and thought it gave them the power of Nika the Sun God, making it one giant misunderstanding which would make Loki want to kill Luffy because he’d be pissed at the misunderstanding
Ever since WCI the fandom has been adopting YC3, YC2, and YC1 as tiering system to grade commanders. YC1 was determined to mean you are on the level of an average Emperor first commander, which was decided to be Katakuri or King level; and the exceptional ones who were above that got called YC1+.
Kind of funny now how like, literally every other Emperor crew who is not the Big Mom or Beast pirates has now defied this convention.
Whitebeard Pirates : Marco is YC1+, Jozu is YC1, Vista is YC2 at least.
Red Hair Pirates : Beckman is YC1+, Lucky Roo is at least YC1, and Yasopp at least YC2
Strawhat Pirates : Zoro is YC1+, Sanji is YC1, and Jinbe with water should be YC2
Blackbeard Pirates : Kuzan is Admiral level, Shiryu should be at least YC1+, and Avalo should at least be YC1
Cross Guild : Mihawk is Emperor status, Crocodile should be YC1+, and Daz Bones might be a generous Flying 6 level.
People saw the Emperors as all rivals and close on the tier list, noticed a pattern of them all having their top 3 guys, and tried to apply the same thought process around that... but it's now beyond evident that not all Yonko crews are built the same and the majority of the characters that hold the "YC2" position within their crews could be realistically argued above King or Katakuri.