Slaanesh, Lord of Excess

When Slaanesh enters the battlefield, for each
opponent, tap up to one untapped creature
you control. When you do, gain control of
target creature that player controls with power
less than or equal to the tapped creature's
power for as long as you control Slaanesh.
Whenever you attack with a creature an
opponent owns, you gain 2 life and that player
loses 2 life.