Catching his scheme before it begins is the best option, obviously.

He has an awful ego; he definitely doesn't make friends; anyone he acts friendly toward- truly friendly-- he's probably plotting something regarding them. As for prevention... [...] ... Whatever I do, imagine what would ruin it, and that's probably what he's thinking of doing.

Unfortunately, as I just want to get us out of here, this could go sour very quickly. Or, well. Will go sour.