The Siphoner

Whenever The Siphoner enters the battlefield
and it was cast, exile all other non-Envoy creatures.
You may cast creatures exiled by cards named
The Siphoner from exile using any color of mana to cast it, if you do it's an X/X black Envoy named
'Envoy of the Siphoner"where X is the creature's converted mana cost.
The Siphoner has the activated and triggered abilities of all Envoy cards you control.