World of Darkness

The World of Darkness (闇の世界 Yami no Sekai), also known as the Dark Ocean, is seen primarily in Digimon 02. Though we do get a glimps of what might be a part of it near the end of Digimon Adventure when Matt and Sora fall into Dark Caves.

At some point between Digimon Adventure and Digimon Adventure 02, Ken is transported into this world. When he submerges his Digivice into the Dark Ocean it changes into a black D-3 and he begins to change into the Digimon Emperor.

In ZT13, Kari is transported there. She encounters Scubamon, which appear to be gearless Divermon, with Evil Spirals on them, but the Evil Spirals did not seem to be controling them but sapping their energies. They said the God they worshipped had done this to them.

She started to try and remove them but an Airdramon with an Evil Ring on it, or at least it appeared to be one, attacked the cave. They ran out. She called out to Tai, Gatomon and TK. T.K., Patamon and Gatomon then broke through to this world and helped out. Under Gatomon's instructions T.K. armor evolved Patamon to Pegasusmon and destroyed the Dark Tower hidden inside a light house that shown a dark beam. This enabled Gatomon to digivolve into Angewomon and easily beat the Airdramon. What had been the Scubamon then mutated into strange creatures (not made clear wether they are Digimon or not) and grabbed Kari saying she should breed with them. Angewomon shot a warning at them and they retreated saying they would return to their God.

Later on, Daemon is banished here. Another odd connection is that on Daemon's cloak is a symbol of the elder gods (the enemies of the old ones) whether this was a mistake, or an intentional link we don't know. Though one may gather from this connection that this means Dragomon can't hurt him.