Mei, Ice Trickster

When you cast Mei, Ice Trickster, tap target creature an opponent controls. It doesn't untap as long as you control Mei, Ice Trickster.
Whenever Mei, Ice Trickster becomes the target of a spell or ability your opponents control, you may pay {u}{u}{u}. If you do, you change the target of that spell or ability.
"You got iced!"