This guy is something that appeared in a few of my dreams. He/they may look like two creatures but he's actually a single being. They're based of Gemini where two beings share everything between each, sensory information and damage/healing.

Doesn't stop them from acting separately like a pair of twins like they are. XD For me, my blue one acts like the tranquil friend while the red one likes to act like the brash friend. I say "my" because I'm sure Duomon as a concept and their own thing can be any two color pairs and personality. My Duomon tends to swap back and forth from using singular male pronouns and plural they pronouns.

He's overall smaller than a Guilmon, around the size of an Agumon or Veemon.

Further slight differences include:
When they are separate my blue is alone or separated, he uses an ice attack for a weak special.
Red uses fire attack for his weak special, and he's an cm taller.
Red also utilizes offense stat slightly better then both of himself as a whole.
Blue is vaguely faster.
Together they use electric attack for their special.

Original art by  RaccoonCube color edits by me.