Faceless Butcher’s first ability isn’t optional. If no other players control any creatures and you do, you must choose a creature you control as the target.

If Faceless Butcher exiles a token creature, the token will cease to exist after being exiled. It won’t return to the battlefield because of the second ability.

If Faceless Butcher exiles a second Faceless Butcher, and then a third Faceless Butcher comes along and exiles the first one, the second one will return to the battlefield. If there are no other creatures on the battlefield, the second will exile the third one, returning the first one, and so on. If no one can stop the loop, the game will be a draw.