The Last Titan Engine

Whenever The Last Titan Engine deals combat
damage to a player, exile up to one target
creature. Draw two cards and you lose 2 life.
Remove 3 Loyalty counters from a planeswalker
you control: Crew The Last Titan Engine. You
may pay an additional {w}{w}{u}{u}. If you do,
The Last Titan Engine gains flying and vigilance
until end of turn, you lose each poison counter
you have, and you gain 1 life for each poison
counter removed this way.