Cosplay attendee in her costume, as Saitama from One-Punch Man.
Saitama is the main protagonist of One-Punch Man and the most powerful hero alive. Saitama faces a self-imposed existential crisis, as he is now too powerful to gain any thrill from his deeds.
Cosplay, a contraction of the words costume play, is a performance art in which participants called cosplayers wear costumes and fashion accessories to represent a specific character.