tbh, i dont think you even need the deso. while it is energy free, i think you woild be better with a savagery on top, and a dawnblaze above the dissolver.
in my first few months of playing, i was a heat/phys hybrid, and i encountered a shield user before they were banned from arena. they used a heat shield that blocked half my damage, but not the heat, and they quit after they shutdowned a few times. the sheild cost them 500 heat...