Gauth, The Cruel

Whenever one or more creatures an opponent controls attack, you may tap any number of snow
lands you control. If you do, they gain -X/-0 until
the end of turn where X is the number of snow
lands tapped this way, then tap all attacking
creatures with 0 or less power.
At the end of each combat phase, gain control of target tapped creature with 0 or less power.
"All bend to the cold"