In a shocking twist, Darkness Number VII was revealed to be Hououin Kyouma, main character of the popular visual novel/anime Steins;Gate. Kyouma makes many cryptic remarks, claiming events are "the choice of Kingdom Hearts." He will form a hostile rivalry with Kairi, mainly due to his insistence on calling her "Kylie." This strange man was sought out by Xehanort for his ability to retain memories from other timelines, allowing him to violate the laws of time travel and change the past. Whenever one of the Darknesses is killed, he laments over not being able to save them, evidently having seen them all die over and over and over again.
In battle, his weapon is a cell phone, and his element is Dr. Pepper; one of his attacks will turn all of Sora's potions into Dr. Pepper bottles and scatter them around the field, where Kyouma can pick them up and restore his own HP. Should you use a continue, he will taunt you over your defeat and pick up using whatever strategy he was using when he killed you, showing that he is aware of the slip in time.
"I am Xehanort! It's so cool! Sonuvagun!"