When it enters or attacks, you have to sacrifice another permanent
If you have a free sac outlet then a Persist creature with Celes is a recipe for infinite ETBs and infinite death triggers
The main question is, do you just go for value with this green land, or go for the full combo-turn and make it a copy of something silly like Omniscience
Krark's Thumb Market Price: $16.43 You're not going to see this too often in Commander, but the relative handful of coin flip decks that do exist will rarely thumb their noses at the chance to ignore a bad flip
Shield of War and Peace (a reprint of Sword of War and Peace) deals extra damage when hitting a player directly and also grants its user protection from red and white
Otherwise, Id look for treasure payoffs, artifact payoffs, and token payoffs