I've been doing more research into Set, and I realized something: Set is one seriously powerful God. Not only was he able to kill Osiris, but before that, he fought and killed Apep seemingly on his own, and on a daily basis. And Apep wasn't a pushover, as very few gods in the Egyptian pantheons ever managed to kill him, much less on a daily basis. Killing a demon god who was basically the Anti-Ra. . . Set is not a god to be messed with. 

Infact, only reason he was kicked off Ra's boat guard was because he asked to be treated better(and threatened to attack Ra as well, but to be fair, that's what most people want to do their bad bosses anyway). Whatever IT is, It'll regret getting in Set's way.