Cast this spell only during combat before blockers are declared.
Untap target attacking creature and remove it from combat. Gain control of that creature until end of turn.
10/4/2004 Disharmony works even if the attacker was not tapped to attack.
10/4/2004 The creature untaps (if it was tapped) before you get control of it.
10/1/2008 The current wording explicitly removes the creature from combat. It is no longer an attacking or blocking creature.
10/1/2008 Disharmony can target a creature you control.
10/1/2009 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).
9/20/2013 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.