They helped Dr.Facilier get the whole city. Then he trick them to believe they would have the whole city. When Tiana broke the amulet, the shadom demons kill Facilier.
Role in the series
The Shadow Demons are amongst the first Heartless created by Chernabog during the first Cartoonian War to serve as mooks for Baron Samedi and the voodoo masks. When Chernabog was defeated, the voodoo masks and shadow demons fled for their lives before discovering Facilier and the Villain League. Shadow demons are a great deal more threatening looking than their cute shadow heartless cousins. They also have the added ability to alter a person by beating up or dragging that person's shadow, as well as their ability to rip out people's hearts to create more Heartless. also, shadow demons can be form from the cruelest villain or Creatures, like Malcon as an exsample. In fact, at one point, Malefor managed to capture one of Facilier's shadow demons, more specifically the female demon with long hair, and used it to possess Cynder to change her into Dark Cynder. When Dark Cynder was destroyed and changed back into Cynder, the shadow demon left Cynder's body and returned to Facilier's control. It was later used again by Facilier to repossess Cynder on orders from Malefor, and left Cynder again when she was cured permanently by Spyro's finisher light move.