He's nasty and rough to deal with and then so many people add into this tempo with stuff like Rhystic Study, Esper Sentinel and Winter Orb and such - don't
Finally, you can spend 9 loyalty to activate: If target player has fewer than nine poison counters, they get a number of poison counters equal to the difference. All you have to do then is add another poison counter somehow - say, by proliferating - and that opponent is dead
If you have your commander out, you can choose both modes, which is a plus
The attack and sacrifice triggers often are fine at their lowest power level with say a 1/1 token, but the power gets jacked way up when you have cards with more power than their mana value like Anticausal Vestige
Dont make my same mistakes however: A white Featherbrained Filcher caught my eye since it generates a Food token when it leaves the battlefield, compelling me to attempt a white-green deck for that reason (black-green is far better for food)