Proculsexual is an ace-spec identity that describes someone who only feels sexual attraction to individuals who they're sure they can never be in a relationship with, such as fictional characters, celebrities, or individuals who they know would never reciprocate their feelings.
Fictosexual falls under the umbrella of proculsexual.
Many asexual individuals may fantasize about relationships with celebrities or fictional characters; however proculsexual refers to individuals who feel strong attraction towards these individuals for an extended period of time, rather than just daydreaming about them, and only feels attraction to individuals they know they cannot be in a relationship with. When they find that it is realistic to be in a relationship, the attraction may fade or go away altogether.
The romantic counterpart is proculromantic.