巨人の掌握

Gaining control of a nonland permanent doesn't cause you to gain control of any Auras or Equipment attached to it.

If Giant's Grasp leaves the battlefield before its triggered ability resolves, you won't gain control of the target nonland permanent at all.

The control-changing effect doesn't expire if another player gains control of Giant's Grasp (although this is likely to cause it to leave the battlefield because it can enchant only a Giant controlled by the controller of Giant's Grasp). The effect expires only once Giant's Grasp is no longer on the battlefield.