MArcomage

There already is an uncommon illusion card by that name.

Perhaps Doppelganger, Skinwalker or Chameleon Spirit (using the same theme as the Wolf Spirit common card) as alternative names. I can't recall if those are taken or not. Also it could maybe have an attack and a Beast keyword, since you're not always going to want the card in the same position as this it might help for it to have some other effect.

I didn't noticed that we already have a shapeshifter. i'll rename my concept "skin walker" as Xenogeist suggested.

I've changed it again to "doppelganger"