A Gummi Bears/Gargoyles (Timedancer)/ The Princess and the Frog crossover.
This story is based on my theory that Dr. Facillier made his deal with his "Friends on the other side" to give himself an immortal life long before TPATF when he feared dying from a disease. The spirits have given him power and immortality as long as he feeds them human souls regularly, so he makes his move on Dunwyn. Meanwhile, Demona (already immortal) seeks the Gummies to help her get revenge on humans as she has learned how the ancient Gummies were driven away. The Bears refuse, so Demona allies herself with Facillier (as they share the same interests and she cannot kill him). At that time, the Phoenix Gate sends Brooklyn to Dunwyn (about a year since his time travels began), and he tries to ally himself with the Gummies to stop Demona, but there's a problem: Because of their encounter with Demona, Gruffi doesn't trust Brooklyn. For the Gummies, this takes place during the year gap in "King Igthorn" (closer to the begining).