As the "dark" half of Ventus's Heart, Vanitas was first much like him. However, due to the suffering he endured by the hands of Master Xehanort, and his desperate desire for salvation, he became proud, cunning, and cruel in order to achieve enough strength to forge the χ-Blade with Ventus, believing that to be the salvation he desires. As such, the lives of others, including that of even Master Xehanort, hold absolutely no value to him, and he shows zero remorse for his actions.