Used give command to give splash potions of simultaneous health & damage. Potion 1: Both potency 124 Potion 2: Both Potency 125 Potion 3: Both Potency 126
Potion 3 behaves as though both were potency 1. Potion 1 kills both undead & live mobs, no effect on EnderDragon, Creative Mode Player, Resistance 5 mob, or Enderman. Heals Wither during summoning mode in 1 hit. Kills wither in 8 hits.
Potion 3: Kills creative and survival mode players, leaving no death message, and dropping experience but clearing inventory. Inventory kept when gamerule is true, cleared otherwise. Kills wither with one potion, even during summoning stage. Kills enderdragon in 1 hit. Kills Resistance 5 mobs in 1 hit. Kills Endermen, endermen die while teleporting.
Video: http://www.youtube.com/watch?v=xLtZuj6rUTM