Mitski, Rural Tinkerer

Whenever your opponent casts a card that says
"draw a card" you may discard a card, if you do
deal 2 damage to target creature or planeswalker.
Metalcraft—if you control more artifacts
than your opponent, in your upkeep you deal 2
damage to target creature or planeswalker.
A wanderer from Kamigawa lost with little hope,
turned into the greatest mind in Kaladesh.