- Scar killing his own brother, Mufasa◊ in The Lion King.
- The Death Star destroys Alderaan◊, A New Hope
- Khaled Al-Asad nukes his own capital city◊, Modern Warfare
- Griffith's betrayal...◊
- The real Alex Mercer unleashing the Blacklight Virus in [PROTOTYPE].
- Shion Izumi killing Tae Kojima in front of Kei Kurono in Gantz.
- Sasuke attempting to murder his comrade out of sheer heartlessness and the SCARY face he makes before doing so, Naruto
- Sephiroth killing Aerith Gainsborough◊ in Final Fantasy VII.
- Kylo Ren murdering his own father, Han Solo.◊
- Anakin Skywalker murders the Jedi younglings in Revenge of the Sith
Image Links / Moral Event Horizon
Some villains really have crossed the Moral Event Horizon. Beware of spoilers.