Proxy war

If 2 players, Until end of turn u gain control of a creature target opponent controls and target opponent gains control of a creature you control
If 3 players, You and target opponent each gain control of a mutual opponents’ creature.
If more than 3 players, You and target opponents choose nontarget opponents to fight. You gain control of one creature. You must attack selected nontarget opponent
If selected creature is tapped, untap.