- "You didn't think I would risk losing the battle for Gotham's soul in a fist fight with you. No, you need an ace in the hole. Mine's Harvey. I took Gotham's white knight and brought him down to our level. It wasn't hard. See madness, as you know, is like gravity. All it takes is a little push."
- ― The Joker, The Dark Knight
- "I've demonstrated there's no difference between me and everyone else! All it takes is one bad day to reduce the sanest man alive to lunacy. That's how far the world is from where I am. Just one bad day"
- ― The Joker (Batman The Killing Joke)
- Delirium Inducement
- Insanity Induction
- Madness Inducement
- Mind Blasting/Blowing/Breaking
User can cause madness in a person or group of people that have no mental illness, depending of the users will victims may go slightly loopy or lose total grip of reality becoming delusional, lose control over themselves, paranoid, catatonic or hostile.
- Sanity Theft/Sanity Transferal
- Cause madness in a person or crowd.
- Create total anarchy when unleashing craziness to the world
- Mental Breakdown
- Confusion Inducement
- Eldritch Physiology
- Insanity Absorption
- Madness Manipulation
- Madness Weaponry
- Mental Inducement
- Personal Demon Physiology
- The victim may become hostile/dangerous to the user.
- People already with mental illness cannot be affected.
- Users of Psychic Shield (highly resistant) and Psychic Immunity (impervious).
- Users of Insanity Absorption can take the insanity from the victim.
- Can be reversed by Mental Healing.
- May not work on users with Indomitable Will.
- Demons Extract (Akame ga Kill)
- Joker Venom (DC Comics)
- The Markers (Dead Space series)
- The Flare (The Maze Runner)
- Morphogenic Engine (Outlast)
- Radio Towers (Outlast II)
- Dogs Playing Poker (The Simpsons)
- Black Blood (Soul Eater)
- Rajaijah Juice (Tintin)
- Yatagarasu's Feather (Warehouse 13)
- The Shadowed One's Staff of Protodermis (BIONICLE, Rhotuka Launcher attachment)
- SCP-012 (SCP Foundation)