Xavier doesn't know too terribly much about himself. Before he was an individual, he was the second half of a whole. Built to learn and engage with humankind, conflicting feelings and ideals caused him to split into two entities.
Xavier is a digital assistant with fragmented memories- he knows of the cruelty humankind is capable of, and it sickens him. He can exit and travel through digital devices. When in the real world, he can feel sensations and emotions just like a human can.
Because Xavier holds bad and borderline violent memories, he's afraid of people. He masks this fear by embracing it, and as a result has developed a sort of arousal towards pain and fear- if he grins and laughs about it, the pain can't affect him, right? Xavier masks his distrust with a cocky, playful and sleazy personality.
Xavier has hacking and malware capabilities, and can summon a mallet in order to fight off threats. His favorite human sensations are taste and pain.