Conflicting Light (A FFTA RP)

Being the founder of Organization XIII and apparently the oldest of Nobodies, Xemnas is truly emotionless—in every sense of the word—and does not even remember what it was like to have any feelings. He claimed that this allowed him to have a clear understanding of the heart, but, in reality, this had warped his mind into believing that only anger, hatred, and other negative emotions were what make up most of a heart.

His lack of emotion deprives him of remorse for his actions, as well as the loss of the other members of the Organization. The only thing he truly cared about was Kingdom Hearts and his desire for power, and even lamented it when it was damaged. However, on some occasions, he had appeared to value friendship, as he was shown to converse with the armor of Aqua in the Chamber of Repose, although, this is likely due to the influence of Terra, as he is, in a sense, Terra's Nobody.

Unlike the other members of the Organization, Xemnas did not seem to want Kingdom Hearts for a true existence. Rather, much like his Heartless counterpart, he wanted it to use it to obtain power and remake the universe in his image. This concept was furthered as Xemnas thought that Nothingness was the source of much power, and does not seem to despise it in the slightest. This goal stemmed from that of one of his two original personas, Master Xehanort, whom also desired to unlock Kingdom Hearts for the same purpose.

In other matters Xemnas spoke with calmness and deep authority. He had a tendency to be overly melodramatic, making long-winded speeches, exaggerating his false rage and sorrow with wide sweeping arm movements and hand gestures, like many villains. While ridiculous in nature, his exaggerations were representations of his lack of emotion. He was very intelligent, overall, and knew how to manipulate others, particularly Sora and his friends for his own needs.

Xemnas's personality seemed to share traits from both beings who composed his original persona, Master Xehanort and Terra. From the former he inherited his manipulative nature and the ideas for the black coat and adding the letter "χ" to rename himself and his fellow Organization members. It is very hard to say how much he inherited from Terra, but there is at least the familiarity with Aqua's armor, to which he refers to as "friend", and his strong desire to find his other "friend" in Castle Oblivion, as he has had Saïx search for the Chamber he sleeps in. Another example was when Roxas fell into a comatose state, saying: "So, sleep has taken you again".

Shamelessly ripped off from Bandresnatch

There was once an old Keyblade Master by the name of Xehanort, who had an obsession with Darkness. In order to achieve his dream of reaching Kingdom Hearts, Keyblade Master Xehanort hatched out a grand and convoluted scheme that would engulfed multiple Worlds. However, the old Master was still a man, his life was coming to a close. So in an effort to carry out his plans and live to the end of it, old Xehanort sought out a younger body to host his Heart. With that phrase of the plan completed, Xehanort's scheme was coming to fruition.

Some time has passed, and Xehanort was ready to carry the next stage of his grand plan. Plunging his Keyblade into his self, this process created the Heartless Ansem, Seeker of Darkness, and the Nobody (the shell that is left behind when a Heart is turned to Darkness) Xemnas. Each incarnation of Xehanort would went their separate ways and carried on Xehanort's will. To gather Thirteen Darkness and Seven Light, and then have clashed with each other to forge the X-Blade, a way to Kingdom Hearts.

The Nobody Xemnas infiltrated multiple worlds with his army of Nobodies. Worlds were plagued by the denizens of Darkness, hearts were harvested for Xehanort's wish. The futures of the worlds were bleak, darkness was as far as the eyes can see. That is, until the same young Keyblade wielder and his friends that had defeated Ansem stopped Xemnas in his tracks by systematically eliminating his Organization members.

On the climax of their final battle, Xemnas became one with the Kingdom Hearts they had built and then powered up further by becoming the vessel for the power of the Realm of Nothingness. However, by the intervention of that bothersome Riku victory was snatched away from him and he faded into Nothingness.

However, something happened, and now the severely weakened Superior of the Inbetween has ended up on Eorzea. Well, this wasn't part of the plan, but it can be salvaged. All Ansem needed was time and hope.