People are seriously underestimateing the Mana Addict + Arcane barier combo, at level 16 (without literally "farming" orbs) it can give you a up to 1.5-2k shield (that's 50%+ of Hp at that level) wich increases survivability and lets you outlast that pesky Illidan, Nova or Zeratul.

Rest is pretty streight forward you can use Verdant Sphere and 2X Living bomb the same hero to initiate in a mass fight. The second Living Bomb aplication detonates the first one therefore spreading living Bomb via Chain talent to all enemyes in vecinity of the target. I've had several situations when Arcane Barrier allowed me to reatreat with low Hp while my pursuers slowly cooked and died behind me via Living Bomb detonation and reaplication by itself.