Imperious Perfect [Champs and States] Avatar Incarnation add an amount of {C}

add an amount of {C} equal to that spell's mana value

Set: Beatdown Type: Sorcery Rarity: Common Cost: {X}{R} This spell costs {1} more to cast for each target beyond the first

but not more life than the player's life total before the damage was dealt

Set: Kaladesh Prerelease Promos Type: Artifact Rarity: Rare Cost: {4} Each player may play an additional land on each of their turns

They only specify the consequences should you fail

Imperious Perfect [Champs and States] Avatar Incarnation add an amount of {C}Set: Champs and States Type: Creature Elf Warrior Rarity: Rare Cost: {2}{G} Other Elves you control get +1 +1. {G}, {T}: Create a 1 1 green Elf Warrior creature token.