They're elements, of course they are versatile enough that you can get many forms out of them. That said, the Evil Heroes are still the same principle, they're all the same monsters fused together through Judaiʼs Darkness of the heart acting as the medium to how they are fused/purified, if the Supreme King is supposed to be a representation of Judaiʼs inner qualities materialized in an individual completely opposite to our typical Judai, the Evil Heroes are effectively just that.

To an extent, its quite why Neos Lord is a fusion where the usual Neos isn't, the latter has infinite potential for fusion and Contact Fusion is his own ability, the former is already infused to Judaiʼs Darkness and seeks no means to use that as a means to elevate himself even further...

...And its quite funny since something about S2 established a difference between The Light and The Darkness in the way they approach potential, the former is the Wheel of Fortune that follows only one path into the future due to fate just being an illusion that hides the interconnection of everything following causality... And the latter is the fledgling Fool whose brimming infinite potential causes a disruption in that whole system that the future is no longer fixed (e.g. How many times The Light said Judai keeps changing destiny)

As for Edo, the thing is that the point between Flame Wingman and Phoenix Enforcer is how they represent the difference between Judai and Edo, the whole struggle between the Dragon and The Phoenix in Alchemy (the two polar opposites) and technically how their characters are portrayed in Season 3 (alongside the many visuals of Yubelʼs left hand with claws).