Six - [Foil, Borderless] Modern Horizons 3 (MH3) Sorcery put two +1/+1 counters on

put two +1/+1 counters on it instead

scientists

Pay 2 life: Put a +1/+1 counter on Bloodtracker

Karn felt more secure about his value to Urza when he realized he didn't need regular trimming

Whenever a spell or ability you control counters a spell

Six - [Foil, Borderless] Modern Horizons 3 (MH3) Sorcery put two +1/+1 counters onReach Whenever Six attacks, mill three cards. You may put a land card from among them into your hand. As long as it's your turn, nonland permanent cards in your graveyard have retrace. (You may cast permanent cards from your graveyard by discarding a land card in addition to paying their other costs.)