(Not much is known about Illness other than he takes the role of a judge too seriously, he is cruel and has a twisted sense of humor, enjoys torturing morally bad people psychologically and physically. He also is impatient and easily angered, getting annoyed when someone thinks that regretting their actions will save them. Also showcasing signs of Dark Empathy, using his understanding of your emotions to hurt you and or manipulate you.likes Torturing sinners Harming others Inflicting fear Having his ego feddislikes Sinners Other EXEsIllness appears as a horribly grotesque version of Sans the skeleton with slight differences in attire.

Illness eyes are dot-sized and his mouth has additional gums. Illness's color scheme is entirely monochrome, his jacket lacks sleeves, and he is missing his slippers. his chest is also filled with tortured souls Causing people to suffer heart attacks If you are to win in a fight against illness, he will cause you to suffer a heart attack. And if you are to loose, you still get a heart attack.

Makes you unable to leave or uninstall the game Once encountering illness, no matter how much you want to leave, something in your mind stops you from uninstalling or leaving the game.

A form of mind control He can numb your mind, cause brain fog and numb critical thinking to those who encounter him. Also can induce feelings of remorse and empathy to those who lack them, just so that his punishment causes an impact to even the most monstrous.

Infect other fangames and games Given from what was shown in Fell Into Illness Sansational illness can extend its presence over other games, and Undertale fangames.

Souls in chest The souls in his chest can be used as weapons as he can summon attacks as Gaster blasters from them.

Casting illusions He can create illusions of anything, preferably uses said illusions to falsely "summon" a dead loved one and use them as a way to guilt trip those it encounters.)