Death Realm

Select a creature you control and a creature an opponent controls, destroy all other creatures.

Then the creature you control starts a free attack against the opponent that controls the other creature, the creature the opponent controls must block.

If the opponents creature has flying, it loses it for the rest of the turn and the creature you controls gains flying for the rest of the turn. The same is true for first strike, double strike, death touch, haste, indestructible, life link, menace, reach,