Killer Party

Killer Party is a horror comedy film released in 1986. The movie was directed by William Fruet. This film is the latest preMay 1986 MGM movie to be owned by Turner Entertainment since 1986 and then owned by Warner Bros. since the 1996 Time WarnerTurner merger

Near the end, its revealed that Jennifer who happens to be possessed by the demon tries to kill Phoebe and Vivia with a trident, but Vivia and Phoebe escape from Jennifer and head upstairs to escape by breaking off the blocked window and escaping to the roof, but then Jennifer appears on the roof and attacks Vivia outside of the house, causing her to fall from the roof and landing on the ground in damage. Phoebe, with a sharpened wooden column, saves Vivia by impaling the possessed Jennifer with the wooden column through her chest, apparently killing both the girl and the demon. However, the film ends with the demon taking hold of Phoebe just before the police arrive and take her into custody. As bodies are removed from the house, Vivia is placed on a stretcher and taken to an ambulance where Phoebe is waiting, still under the demons control. Vivia begs not to be put in the ambulance with Phoebe, but her screams are ignored. The movie ends when the ambulance doors are closed and the vehicle drives away as Vivias cries continue. It is left to the audience to wonder if Phoebe will kill Vivia at the Hospital or at a certain point.The movie was originally to be called April Fool, but the title was changed to Killer Party when Paramount announced their own horror film called April Fools Day. ........

Source: Wikipedia