Possession Engine

Steal effects have always been priced against the fact that the creature you take is still a creature: it can swing, it can chump, it can be sacrificed for value. This design refuses all of that. The stolen creature is neutered the moment it changes hands (it can't attack or block for as long as you keep the Vehicle), so you are not borrowing a threat, you are removing one. That reframes the effect from a tempo swing into a pseudo-removal spell that happens to leave a body on your side of the table, a body you can then crew with. Crew 3 is the string attached: the theft holds only for as long as you control the Vehicle, and a Vehicle is uniquely fragile as a leash because artifact removal, not just creature removal, snaps it and hands the creature back untouched. Most control-magic effects worry about the opponent regaining their creature through bounce or a sacrifice outlet; this one instead ties the whole arrangement to a permanent type that opponents have their own dedicated answers for. What you have built is a durational steal that reads as an animated prison, and it turns the classic question of "how do I keep the creature I stole" into "how do I protect the box I'm keeping it in."