When an individual tells people about awful things they've done as if they are bragging, but rather than impressing the intent is to shock or scare people

Someone who is possessed by clout chasing. The original human is now gone and a demonic entity that feeds on clout is all that is left. An empty shell with no control of their actions, forced to blindly react to situations they think will bring them attention.

When someone is such a sociopath, they brag about their cruel accomplishment to others, just for the lulz.