Dr. Nefarious' Heartless

When Xehanort and The Hearts of Darkness union laungh an attack on the generator of the universeal bounderies after they left Rourke's Heartless to battle the lougers, Xehanort easily scares of the Members of Team Nefarious and desimated the nefarious troopers and the hornets. Nefarious was forced into a corner, makes hasty escapes, but was quickly beaten and overwhelmed by Frollo's Heartless, then, In Nefarious' weak and vulerable state, Xehanort exposed Nefarious with his keyblade, turning him into the Nefarious Heartless, and makes him guardian of the generator as Xehanort uses it to open the gates to the world that never was, and begin the great cycle by having Kingdom hearts sucked away the worlds, and begin creation of their design.

Eventally, when the lougers first reach the main gate to the world that never was in the corrupted generator, they have to fight Nefarious's Heartless, and after a very climatic battle, Kairi was able to use her keyblade to free Nefarious for his curse, with the Doctor expression a very lovelust gratutiude, to Kairi's annoyence and newfound regret to do so. However, Nefarious becomes upset that Team Nefarious promise to leave the generator alone in return for his return... but quickly lets it go when it opens a new world of possabiliys for him,