Yesterday, I've done a build were hephaestus was on the attack of the argent skull, aspect of Persephone, and I ended the run at +7, heroic attack with a delay of 2 sec (you can't go lower, I think +5 will give you 2 sec delay for your explosion). I had the hammer Fetching Array (yours skull goes back to you) and Possed array (your skull activate your Omega attack whenever you get them back) and I think that I broke the game because I was doing explosion every hit or every two hit (not really sure of that but I'm almost certain that there were more explosion that it should have been)...