Stensian Sanguinist // Exsanguinate - Extended Art [SOC-78]

Whenever you attack, target creature gains deathtouch until end of turn. Whenever that creature deals combat damage to a player this combat, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.) // Each opponent loses X life. You gain life equal to the life lost this way.