The gaze of a Jester drives most humans insane
Jesters are the cackling, gleeful manifestations of the insanity of the Abyss, and a commonly feared type of Other. Always giggling happily to themselves, they find nothing more amusing than trapping a Sorcerer in a terrifying situation and watching them panic, or tortuturing a human until they die from the pain. Purely sadistic beings, they use their excruciating gaze to playfully murder the beings they ensare, laughing insanely the whole time. Everything is amusing to them, and nothing more so than suffering.
Aside from their surprising strength and sharp claws, the main weapon of a Jester is their gaze, the unblinking eye in the center of their skull burning with abyssal energy. All they need to do is look at someone, and white-hot pain will sear that person instantly, pushing them to the brink of death within seconds. The Jester then lets them recuperate just for long enough to stay alive, and recomences the torture, which can last for hours. Most people who have survived the torture of a Jester are found to be completely insane, murmuring incoherent gibberish with a pained and permanent grin on their features.
The Jester's greatest strength is also its greatest weakness. When their eye is damaged, Jesters wither away within seconds, whimpering in pain. They are also extremely sensitive to bright light or Light magic, which will likely blind them, and in doing so rob them of their most powerful weapon.