Psychic Operation X

Suguru Noyama is a student with psychic powers going up against a criminal known only as X, backed by Magane Pulse, a psychokinesis user from the Superpower Countermeasures Office. The catch is how his abilities actually grow: by using clairvoyance and thoughtography to watch Pulse-chan undress, and by witnessing the various rough fates X puts her through.

There's no combat here. You walk the map, trigger events, and let your psychic level and the choices you make branch the story toward one of several endings, so the strength you build doubles as the thing steering the plot.