Showdown at Drufohx

Whenever a Gadget enters the battlefield under your control, you may deal damage equal to its converted mana cost to target creature or player.
Whenever a permanent you own if put into a graveyard, an opponent may have Showdown at Drufohx deal 3 damage to them. If they don't, exile that permanent.
You may cast nonland permanents exiled by Showdown at Drufohx, they cost {2} less to cast.