Yowch. This is easier to cast than first strike + deathtouch has ever been. Voracious Cobra (4 mana, 2 colours) is the iconic version, and as jmgariepy taught us there's also Glissa, the Traitor (3 mana, 2 colours but one doubled, mythic + legendary), Nirkana Cutthroat (12 mana), Pestilent Kathari (6 mana, 2 colours, temporary) and the new Master of Cruelties (5 mana, 2 colours, mythic). I'd suggest this should be 4 mana as comparable to Voracious Cobra. And that's only if you're really sure you want an invincible blocker like this as low as uncommon in your set.