A very angry Monitor?
Thanks. Atrocitus was actually my guess (based solely on google image search, I’d never heard of him). Kind of weird that they used someone so recent, among all the classic characters. If they wanted a Green Lantern villain, why not Sinestro?
As for the art, my mother-in-law bought the shirt for about 3 bucks with her Kohl’s employee discount, so I can’t be too picky. 
That’s what I’d have guessed. Atrocitus is after my time.