@Riger I'm judging him by what I see in the manga. Anyway, even if internal dialog may sound smart, if his actions are the same as in the novel then I wouldn't consider him smart. He never really anticipated trouble, instead just reacting to everything. A smart character is someone who is proactive, not reactive. See Nie Li from Tales of Demons and Gods. He anticipates problems and prepares for them.
that was unexpected turn of events but he kinda made a good choice there. Now he can peacefully spend time in human territory and if sth bad happens MC can just wipe whole demon army.
@Miranox
Choosing someone doing a 'redo' isn't a very good argument of planning ahead. Nei Li didn't plan for crap in his first go through, and pretty much everyone died including him.