The hero character gets some sort of apparel that seems to be great and useful, but it's really sentient, evil (or at least mischievous in the way Muggles
would consider evil) and it wants to turn the hero to its own ends. To this end, it begins manipulating the hero's mind. He becomes less sunny and more grim. He becomes less playful and more violent. Eventually the suit and or its wearer begin referring to themselves as "we". At that point, the hero may very well realize there's a problem. Or the damage is done, and the hero's tipped over, and will have to be forcibly separated from his new item.
It needn't always be an article of clothing. It could be a gem or jewelry. In fact, they are often the worst offenders; they are ensorceled to whisper seductively to a prospective wearer, the better to get into position to take over the victim.
This trope has a fine lineage, sharing relations to Enemy Without
, Evil Costume Switch
, Clothes Make the Superman
, and Evil Makeover
. The difference is that the person who ends up the maniac in question started out a good guy and had no idea that the article of clothing would drive them evil/insane.
- Spider-Man's black costume is sentient and evil. It used to take his body walkies and swinging around while he was unconscious, and it turned his personality dark. For that matter, it's true of all the symbionts from the Marvel Universe. Venom is kind of an Anti-Hero, but to my knowledge there isn't a symbiont suit that is nice and do-gooding.
- In Spider-Man 2, Otto Octavius becomes Doctor Octopus as a direct result of the failsafe burning out protecting him from the influence of his sentient WALDOes.
- Jenny's "human skin" on My Life as a Teenage Robot was fixated on being normal and beautiful and refused to let Jenny use her robot powers to save people when the situation warranted.
- A police officer on Superman: The Animated Series is a milder example. He was given a combat suit to use that ended up addicting him. He shaved his head, the better to interface with it, began referring to himself as "we" and got violent when separated from the suit or thwarted from using it. It also made him territorial to the point of being willing to beat up on Superman.
- Cash on Ben 10 Alien Force ended up with one, in the form of a cybernetic robot glove that could build itself a new body and compel its wearer to mindless violence.
- The title artifact in The Mask and Son of the Mask is a partial subversion. It is an item of Loki, god of mischief. So when it takes pver the gentle dreamer Stanley Ipkiss, it turns him into a mostly-harmless cartoon maniac, who indulges in one act of implied horrifying violence. Dorian, however, is bitter and violent, and the Mask only magnifies those bad traits to worse.
- The mother of Manny Rivera is recovering from an addiction to a pair of gloves she wore as the superheroine Plata Peligrosa, that turned her into an action junkie.