SOC-78 Stensian Sanguinist

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.)
//Prep//
Exsanguinate

Sorcery
Each opponent loses X life. You gain life equal to the life lost this way.