I don't know: the term axis suggest more cooperation between like-minded and "evenly" matched parties than straight-up dominance/ subordination.
For all we know, Doom might consider himself a "partner" to Red Onslaught, not a subordinate.
Anyway:
Sabertooth (X-verse)
Loki (Asgard)
Doom (FF)
Carnage (Spider-verse)
Red Skull (Avengers)
It's not really that incoherent from this perspective, a lot of corners of the marvel universe seem to be represented.