Re: DC's New 52: Reviews and Discussion (Spoilers welcolme and likely)
Did you read Relic's Villains Month book? It fleshes him out quite a bit. He's nowhere near the complexity of say, Sinestro, but he's at least more interesting, and his motivations far more clear than Volthoom. I really felt Volthoom was a weak-sauce villain for the finale of such an epic run.
"In Brightest Day, in Blackest Night, no evil shall escape my sight. Let those who worship evil's might, beware my power: Green Lantern's light!"