My Crushing Masterstroke

When you set this scheme in motion, gain control of all nonland permanents your opponents control until end of turn. Untap those permanents. They gain haste until end of turn. Each of them attacks its owner this turn if able.

"Do you see the faces of those you once loved among my legion? You will join them soon."

Duskmourn: House of Horror Commander

Archenemy Schemes

Each of those permanents attacks its owner if able, not necessarily the player you gained control of it from.

Each of those permanents that is a creature at the time your declare attackers step begins must attack its owner if able. This includes permanents that became creatures after you gained control of them. Any of those permanents that aren't creatures at that time can't attack.

If one of those creatures can't attack its owner that turn due to a spell or ability (such as Chronomantic Escape), you may have it attack another player, attack a planeswalker an opponent controls, attack a battle an opponent protects, or not attack at all. If there's a cost with having that creature attack its owner, you aren't forced to pay that cost, so you may have it attack another player, attack a planeswalker an opponent controls, attack a battle an opponent protects, or not attack at all.

If, during your declare attackers step, one of the permanents you gained control of this way that's a creature is tapped or is affected by a spell or ability that says it can't attack, then it doesn't attack. If there's a cost associated with having that creature attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either.