The very first game of the modern series has the Prince unleashing the Sands of Time and turning his father into a horrible Sand Creature complete with a distorted Slasher Smile, forcing him to kill off his only family.
While the glowing save points in The Sands of Time give the Prince many helpful visions of the future, some of them are pretty much bordering in this trope. The game itself has a strange tendency to give the player a Mind Screw by premonitory visions that show you exactly how to traverse the incoming platforming section and what enemies to expect. However, as the game progresses, the visions become increasingly ominous, cutting away to Farah in a suspicious way and occasionally showing her death. Even the Prince himself is shown to die in a few visions. This of course plays on the gamer's forged trust on said visions and shows how even the game can punish you for abusing time travel.
Farah's death is nightmarish considering she lets herself die to help the Prince who ends up rewinding time to save her, but ends up unleashing The Dahaka for his troubles.
The Hassansins' Leader Zolm, and his creepy talent involving the use of snakes both in and out of combat. Though his suffering a Family-Unfriendly Death due to Tamina forcing one of his own snakes to bite him, in the eye no less is very gruesome.