The Countering Runner

Legendary Creature — Merfolk Gamer3/7

Spells you cast that would counter a spell cost {U}{U} less to cast. Whenever a spell an opponent controls is countered by a spell or ability you control, draw a card. The Countering Runner deals 2 psychic damage to that player. (Psychic damage doesn't cause loss of life, but a player who's been dealt 20 psychic damage loses the game.) Ready to run (You can have two commanders if both have ready to run.)

Not legal in Commander

View The Countering Runner on Scryfall