I can believe that perhaps you never witnessed this issue back then but I assure you the problem was always there. The Expo/Crypt issue is a flaw in Perblue's original algorithm. It just affects more people now as it has been left unfixed for so long.
Medusa, Moon, Cyclops. These are the heroes I would recommend that you focus on. Get them charged (overcharged) early. Leave Auto off on the early stages so you can stockpile energy. When the going gets tough, turn Auto on and Moon should stop the opponents in their tracks and keep them there while Cyclops and any other damage heroes you can muster whittle them down. It can be done.
Other energy support heroes worth considering: Dragon Slayer, Forgotten, Void, EE.
Lower priority IMO, but at least one of: Wolf, Fox, KK can sometimes clinch a fast opponent.
Also, Kraken can be very handy sometimes even without being promoted. I still keep mine at Purple4 just for fun, and he's just as effective for what I use him.