The Lock

Apperance/Personality
The Lock appears as a, simple enough, giant U-Shaped Lock hooked onto the Target's Heart. As with most Stands, only people with Stand powers can see it, even the afflicted has no idea it is there. It has no personality other then serving Tamami Kobayashi, and displays even little of that, seeming to have absolutely no personality.

Powers
Guilt: The Lock's only ability, by making someone feel guilt, Tamami can then summon The Lock, and hook it to the person. Afterward, their guilt on it is multiplied continuously, represented by The Lock growing bigger and heavier, until the victim becomes so guilty they commit suicide. This does not even require the victim to be guilty about something they did, rather, he is able to make Koichi's mother almost commit suicide by making her feel guilty about her son.