I think Loki Is clearly the villain of Erbaf. Or if you want, the main fight Katakuri-like.
There are a billion hints for this, form the Destoryer Nika (Loki)/Liberator Nika (Luffy) to Loki having precisely the worst power for Erbaf, which scream final countdown and foreshadowing:
Do you think this is just for the lol of It? That the "greatest weakeness" of Erbaf won't have any relevance? That the Nika thing won't have one? And so on.
Idk why people are all worked up for something we have basically always known (Harald being fishy). It has always been like this and still Loki has always been the clear menace of this arc.
Surely not the Holy Roppo, who are totally unable to be serious enemies After Shamrock went away.
And It has already been
years since Kaido. EH was already an arc whitout a main enemy, do you think Erbaf can be one too?
And the only main enemy, with a million hints, Is Loki.