The final boss of Survival Expansion III, Herobrine, requires a Neptunium Pickaxe and a Titan's Flame. The Neptunium Pickaxe has the ability to break bedrock by pressing "F" while holding it. You must use this ability to open a hole into the void in the overworld. Jumping into the void will bring you to The Void dimension. You must be careful, though, as the only way to leave this dimension is by dying or killing Herobrine. In the center of the void, at coordinates 0, 0, 0, lies Herobrine's Altar. The altar can be lit with the Titan's Flame. Lighting the altar will summon Herobrine. Killing Herobrine marks the end of Survival Expansion III.