喜怒无常

Edwards was a dangerously volatile character.

爱德华无常，十分危险。

He is a complicated man ——moody, mercurical, with a melancholy streek.

他是一个性格复杂的——无常,反复多变,忧郁寡欢.

He became moody and unreasonable, flailing out at Katherine at the slightest excuse.

他变得无常、不可喻，为点鸡毛蒜皮的小事就殴打凯瑟琳。