Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.
![Karn, the Great Creator [War of the Spark]](http://tothetablebgc.myshopify.com/cdn/shop/files/3ec0c0fb-1a4f-45f4-85b7-346a6d3ce2c5.png?v=1776361270&width=1445)
