He seems to be extremely confident in himself, seeing as how he walked into the Gods' area and sat down in Hades' chair(although he did this due to being clueless as to where his waiting room was).
He's also extremely proud of his rank as Emperor, to the point of brazenly ordering Ares and Hermes to kneel before him and show respect. Qin Shi Huang is also quite fearless and daring, attacking Ares without being afraid of the God and still ignoring him as if he were nothing.