Christian Humber Reloaded/WMG

Christian/Fluffy/Blade/whoever is a pawn in GLaDOS's attempt to destroy the world
Think about it: How many times is a major event caused by "a portal opening" for no reason? I say GLaDOS was trying to destroy the world by creating a power-crazed, completely amoral freak of nature. And by the end, it succeeds.

"Christian Humber Reloaded: Now You're Thinking With Portals."

The experiments on Vashblade were part of a secret government Mary Sue-producing project.
One day, George Bush read a fanfic, which got him thinking: wouldn't it be nice to have a Mary Sue fighting for him? So he started up a secret project dedicated to making Mary Sues, which resulted in Vashblade Dragonfang, Chridon and presumably others who didn't quite make the cut. Of course, they quickly got out of control... or did they?

In accordance with the above, George Bush had a hand in every major event in the story.
Simply put, the random portals to other worlds, various Ass Pull powers out of nowhere, the resurrections of various enemy forces and other such events were part of a complicated plan by George Bush to create a God Mode Sue. Bush even directly states that he summoned Chaos near the end to 'continue research on Vashblade's abilities', so at the very least it wouldn't be unreasonable to assume that Bush was keeping tabs on Vashblade's development, and from there it's not much of a stretch to assume that Bush at least had a hand guiding part of Vashblade's life. Once he got his God Mode Sue, Bush would then presumably either find a way to control Vashblade, or take Vashblade's powers for his own, using them to conquer the multiverse or something. Naturally, the unpredictability of Chaos combined with his experiments being too successful in creating a Mary Sue led to Bush's downfall, but due to the nature of the multiverse in most works, there's a universe out there somewhere where Bush was successful in becoming Vashblade's Kid with the Leash...