A Burst build with Balor, Shingen + Raging Assault would be excellent when healing isn't required. Eventually you could sub Thanatos for Satan and run with Osiris instead of Balor, allowing you to run Ambush instead of Raging Assault. Sadly Satan's DEF down is probably too low right now to enable easy clears of Rank 4 Accessory Quests. Maybe if you had the -10% DEF eidolon?