Karn, the Great Creator's passive ability is a one-sided Null Rod (good lord why are all the War of the Spark prison planeswalker passives one sided?), completely denying a player access to any activated abilities on artifacts
So instead, I'll just play Sarkhan as a big, fat, Dragon beater who threatens the other stuff
From the Amaazon product description: "The hustle and bustle of the city turns into havoc as Mega Floette ex brings turmoil to the streets
Creature - Horror Color tag templates(None) Fate Unraveler Whenever an opponent draws a card, this creature deals 1 damage to that player
If you are looking for something longer-lasting, I recommend Dragon Shield sleeves
When it enters the battlefield, this two-drop creature creates Treasure tokens equal to the number of artifacts or enchantments your opponents control