Gosuto

Gosuto are the main monsters in Supernatural Stars Pretty Cure which first appear in episode 1. They are usually summoned by the villains possessing the pinkerflies to take over someone's object which blackens it and to make a blackerfly which creates a Gosuto. However, if a Pretty Cure manages to take the blackerflies away from the villains, the end result will have the Gosuto be purified.

List of Giant Gosutos
After Vampin gets empowered, he can now turn a victim into a Gosuto by darkening his or her heart with his weapons and then enlarges them to become a giant version of a Gosuto with a gray heart on its chest.