Traitorous Blood

The trample rider is the line that separates this from the Threaten template it inherits. The basic steal-and-swing design, going back to the original Act of Treason, hands you a creature for one attack and leaves the unblocked path your problem to solve. Bolting on trample answers that inside the card: the borrowed body stops caring about chump blockers, because the haste lets it attack the turn you take it and the trample shoves the rest of its power through whatever the opponent throws in front. Untapping it closes the other gap, letting you commandeer a creature that was held back on defense and redirect it into immediate offense. The arithmetic is brutal once a sacrifice outlet is involved: take their biggest threat, swing, then feed the borrowed creature to the outlet before the end-of-turn clause hands it back, so you collect both the body and the attack while they get nothing returned. The price is that it stays a sorcery. It cannot ambush combat or steal a blocker mid-attack the way an instant-speed effect could; the borrow happens on your turn, on your terms. That sorcery-speed limit is precisely what keeps the card honest as a tempo-and-aggression tool rather than a combat trick: you commit to the steal before the opponent has acted, and you live with the board state you read. It is a loan effect that assumes you already wanted to attack and already know where the borrowed creature goes when the turn ends.