Kari Zev the Infamous

Kari Zev the Infamous gets +X/+0, where X is
the greatest converted mana cost amongst
Vehicles you control.
At the beginning of combat on your turn, gain
control of target artifact an opponent controls
with converted mana cost less than or equal to
Kari Zev's power until end of turn. Untap that artifact. It gains haste until end of turn. If it's a Vehicle, it becomes an artifact creature until end
of turn.