The Heart of Darkness

The Threshold Key - a key of pure nothingness - unlocks the final gate. You step into the Heart of the Void, and reality dissolves. There is no light, no sound, no time. Only darkness, and the Corruptor's presence. Archangel Zariel's voice reaches you from impossibly far away: "You carry the key items of all five layers. The Abyssal Key, the Lantern of Souls, the Soul Reaver Blade, the Forge Hammer, and the Threshold Key. Together, they can be forged into the Voidheart Crystal - the only thing that can unmake the Corruptor. But first, you must reach its avatar: Bakragore the Devourer."