Realm of Shadow

The Realm of Shadow is a desolate wasteland without hope and is the home of many dark demons. After dethroning Unicron, Megatron sent Johnathan Tangelo (then known as the Phantom ) here to enslave the demons of the realm and add them to Megatron's grand army. He also hid the Shadow Crystal, the very crystal he used to impriosn Unicron, deep within the castle at the center of the realm. This castle also served another purpose. It was somehow connected to every world in existence, from every universe imaginable. Whoever controlled the castle could go wherever they wanted whenever they wanted to. John then used this to gather villains from across the multiverse to create a grand empire whose main purpose was to stop Megatron from gaining control over the entire multiverse.

This realm is also home to the Valley of Sorrow, a sacred place used by heroes of the past to determine their worthiness by having them overcome the darkness that resided within each of them, piting them aginst their darkest fears and worst nightmares. Johnathan led Angemon and Angewomon to the valley in order to clense their hearts of darkness. The darkness released from the two angels then released Unicron from his crystal prison. John had intended this from the beginning, hoping that Unicron would exact revenge upon Megatron. This plan quickly backfired, and John ended up sacrificing his own life so that the angels and their friends could flee to the safety of Cybertron.