The Blackwake Stalker

Crew 4 (Tap any number of creatures you control
with total power 4 or more: This Vehicle becomes an
artifact creature until end of turn.)
Whenever The Blackwake Stalker deals combat
damage to a player, sacrifice all other permanents
you control and discard your hand. Exile the top
six cards of your library. You may cast any
number of nonland cards exiled this way
without paying their mana costs.