Alright, User, you asked for it. "I'm a computer program who was summoned to an interdimensional hub called Nautilus," Clu said. "I spent several years living there during which time I learned a great deal about the User world, vastly expanded my original parameters, and gained a number of significant upgrades which allowed me to- among other things- travel between dimensions at will. After helping to restore full functionality to that interdimensional hub by assisting in the defeat of an entity who wanted to turn all of reality into glass, I left there to explore the various worlds, partly out of simple curiosity and partly to repair any Flaws- areas where the fabric of reality has been damaged- that I came across."

"The latter is what led me here. I was traveling between worlds and detected a space-time anomaly. I wanted to make certain that it wasn't a Flaw or a potential one, or to repair it if it was. Normally I'm undetectable by the inhabitants of the worlds I visit unless I choose not to be, so I wasn't expecting my visit to cause any trouble, but apparently there's some factor with the anomaly that I didn't account for though, and well... here we are."