Personally I'm now considering a gnome conjurer PC who suspects that all in-setting lore concerning demons is tainted by anti-demon bias perpetuated by prejudiced conjurers. The tomes of demonology say all demons are Chaotic Evil and that they don't reproduce or have families, but why should he trust these accounts?
Despite never summoning a demon that didn't want to immediately kill him himself, he can't in good conscience extrapolate that all demons are Chaotic Evil. Maybe demon summoning spells only summon Chaotic Evil demons? Maybe these demons have families and are enraged that they've been magically separated from them?
He's heard Orcus is Chaotic Evil, but according to who? Bigots with anti-demon prejudice?
His long-term goal is to embark on a lengthy expedition of the Abyss to learn about demons first hand, attempting best he can to resist the prejudiced anti-demon beliefs he's been exposed to all his life. He wants to learn the truth for himself and search the less documented layers of the Abyss for good demons.
Of particular interest to him is the 260th layer of the Abyss, "The Green Abyss", whose demon lord Alrunes is said to be a patron of protection and sisterhood.