For four mana, you get a 4/4 that lets you sacrifice a creature on attack to add Red mana equal to its power
Serra Paragon I feel like Ive been praising this card almost non-stop since it first came out
On top of this, if youre using her as your Commander, her mono black color identity can be rather limiting
For example, if there are two +1/+1 counters on Aerith Gainsborough and it gets three -1/-1 counters, you'll put two +1/+1 counters on each legendary creature you control when Aerith Gainsborough's third ability resolves.
You might need to use colored dice to keep each pair of dice clear so you can ignore one roll from each pair
Koh, the Face-Stealer Holy Ravenous Chupacabra, I clearly don't know much about Avatar when did No-Face show up in the series