XIII機関
is the leader of the original Organization XIII, ranked first as the . First appearing in "Kingdom Hearts Final Mix" as an optional boss labeled , he is identified as the Nobody of Terra-Xehanort, originally Terra who became a host for Xehanort's heart, while his name is derived from Xehanort's alias "Ansem". He uses the power of nothingness to phase through solid matter and wield a pair of "ethereal blades", two red beams of light generated from his palms. He also commands the "Sorcerer" Nobodies.