Disharmony
Legends — rare
Instant
Disharmony rulings:
2013-09-20: If a turn has multiple combat phases, this spell can be cast during any of them as long as it’s before the beginning of that phase’s Declare Blockers Step.
2009-10-01: If you cast Disharmony during an opponent’s turn, you may then block with the creature you gain control of (assuming there’s an attacking creature it can block).
2008-10-01: Disharmony can target a creature you control.
2008-10-01: The current wording explicitly removes the creature from combat. It is no longer an attacking or blocking creature.
2004-10-04: Disharmony works even if the attacker was not tapped to attack.
2004-10-04: The creature untaps (if it was tapped) before you get control of it.