I've gone something like 8-2 against Serket, because once I get a Shield and Hourglass, I can Hasten to enough SoG's to nullify his 10-20 poison counters. I don't care about Eternity, just keep trying to save for Hourglasses, Shields and SoG's. "Very Easy" might be a bit kind, but he's at least "Easy". If nothing else, he's easy in the manner of being simple.