- Nightmare Fuel: The game's virtual reality is based on "hypnotic induction" - in other words, the hardware makes you hallucinate the game so you experience everything in first-person. It can even manipulate your perception of time. Yun falls prey to a fear effect that leaves him trapped in an extended nightmare of being chased by countless undead spectres, despite only lasting a few seconds objectively. Later, newbies Raina and Al are trapped and stunned by a group of PKers, unable to log out while the other players torture them by constant attacking and healing to grind up their own Senses on helpless victims. The potential abuse of hypnotic induction VR in a system that doesn't let you leave on your own terms during a "combat" situation (ostensibly to prevent rage-quitting or cheap escapes from bad fights) is disturbing.
- The Thorn Token enemies during the Fairy Quest are downright nightmarish. They start as vines from a strange, parasitic rose plant that sprout randomly out of the ground and force themselves into the bodies of other monsters. The vines and thorns spread throughout the victimized monster's body, turning it into a jerking, creepy puppet with rose blossoms sprouting out of their skin or eye sockets, and these monsters then try to bite players to steal health and force more parasitic vines into the wounds.
YMMV / Only Sense Online