Darkness Beyond Time

-The Darkness Beyond Time exists as a repository of discarded timelines of the
Keystone Dimension.
-As do Pocket Dimensions, the Darkness Beyond Time's timeline runs 
"perpindicular" to the outside world.
-Schala is transported here in the Keystone timelines in the Ocean Palace
incident.
-Lavos's future within Keystone PD-1 is transported here upon Lavos's defeat in
the Keystone timelines.
-Lavos, even in his defeated and condemned state, is able to fuse Schala onto
himself to create the Time Devourer.
-The Time Devourer begins maturing.
-The Darkness Beyond Time remains the same for both the Home and Another
Dimensions upon the Keystone Dimension's split.
-Serge's party arrives here via the Time Egg and possibly the Frozen Flame, and
defeats the Time Devourer.
-Schala is freed, and Serge's party is returned to the Ideal Timeline.

From: Chronology