Sendor, The Dark Wizard

+3: Destroy Target permanent, its controller or a planeswalker they control gains 3 life/loyalty
-7: Destroy all nonland Permanents, for each permanent destroyed this way, you may either gain 2 life or lose 2 life.
-15: You may activate this ability at the beginning of your upkeep, if you have 10 life at the end of your upkeep, you win the game.