Is there a Magic intro deck that focuses on lifestealing?
One of the clearest "life stealing" mechanics is Extort, which is a triggered ability permanents have that says


  Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain life equal to the total life lost this way.


Extort is from the Return to Ravnica block, and there were two intro packs built around it and related mechanics: Orzhov Oppression from Gatecrash and Orzhov Power from Dragon's Maze.