"The Immaterium would likely try to convince us of its reality, the better to trick us." The Archenemy was cunning in the ways of deception. Which meant that it's Chaos until proven otherwise in Gadriel's mind.

"Tzeentch is the Lord of Change, instability and deception incarnate." He also looked like a weird bird headed human. "I have faced him before, through one of his sorcerors." It did not work out well for them.

"Do you not have evil gods where you are from? Or are you in blissful ignorance of the nature of evil?"