Question about character mechanics: Are skills tied to hero models, or granted entirely by your identity?

Got a quick question about how characters and abilities work from the preview clip.
Are the characters in the trailer just different visual models for players to control—where skills are granted entirely by assigned identities (different identities have different skills, character model affects nothing)? Or does each character model actually have its own unique set of skills?
Curious to see how they designed this system!