She's in the command zone for her two triggered abilities: whenever you cast a noncreature spell with mana value three or greater, she deals two damage to all opponents and you gain two life
Easily one of the top-tier Sun & Moon sets
Dissolve is the twist on that familiar mechanic, letting you to pay the mana value of the exiled creature (plus an extra black mana) to move it from exile to the owners graveyard
When it enters the battlefield, you gain three life and also three energy counters
You can only kill black creatures, or nonblack creatures, under particular conditions, say
Later, in the second half of the game when the world is thrown into ruin, the party discovers Terra in the decrepit town of Mobilz