ok i know many people post this already saying Xehanort guardian is MX or master eraqus but i think its terra guardian maybe anyway you guys remember ventus darkness vanitas he didnt have face he was like any heartless yellow eyes until sora connect his heart to ven i think terra darkness is the guardian he release his darkness vs MX and the guardian comes out vs aqua well xehanort was inside him that time but MX did unleash ven darkness maybe he did same with terra when he was inside well wt u think of this theory