Listen to Dark Impetus: Young Xehanort Boss Theme online. Dark Impetus: Young Xehanort Boss Theme is an English language song and is sung by Patrem. Dark Impetus: Young Xehanort Boss Theme, from the album Reminiscence of Kingdom Hearts, was released in the year 2016. The duration of the song is 4:54. Download English songs online from JioSaavn.