Tik and Tok, Treasure Raiders

Whenever an artifact an opponent controls becomes the target of a spell or an ability you control, gain control of that artifact for as long as you control Tik and Tok.
At the beginning of your upkeep, if you control 20 or more artifacts, you win the game.
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"Hurry up! I don't wanna get roasted again!"
"Then quit yer movin'!"