Listen to Demon Slayer: Infinity Castle - Main Theme (Epic Version) online. Demon Slayer: Infinity Castle - Main Theme (Epic Version) is an Instrumental language song and is sung by Paul Drew. Demon Slayer: Infinity Castle - Main Theme (Epic Version), from the album Demon Slayer: Infinity Castle - Main Theme (Epic Version), was released in the year 2025. The duration of the song is 5:07. Download Instrumental songs online from JioSaavn.