The ability triggers whenever a player casts an instant or sorcery spell that targets only Mirrorwing Dragon and no other object or player
Having it in the command zone is nice, but to me most of these Background enchantments feel best in a deck led by two creature partners so they can both apply the effect
Its not limited to sorcery speed, either, so you can do this in response to removal to change it into a copy of a Legendary Equipment, sending the original to the yard
Lifegain Payoffs Aetherflux Reservoir serves as a way for you to put some of your extra life to good use, and it also gains you some life itself
There are multiple cards in most sets that are white and gain life
This is where Combo Shift and Duo Shift come in, letting characters like Sulley and Boo shift together onto a Team card, mechanically reinforcing the set's teamwork theme