This is going to cost you a lot to get the max dEEpz but here's how it's done.
This is a quick PVE rundown, PVP includes use of other skills (petrify, reflect scales etc)
3k spell damage with entropy:
Dual Wield one bar - reason being DW gives heaps more Spell damage than Staff, and also you can have crit traits on your swords for a boost if they're crafted - like Torugs. (I recommend stygian or torugs swords)
Inferno on 2nd staff. I usually try and have staff+whip+standard on the same bar so I can weave medium attacks with whips and also receive the Ardent Flame Fire Damage bonus that whip gives Standard.
Your mission is to stack your Damage Over Time effects on the boss, while maintaining your buffs, crowd controlling and AOE the ad's when the tank groups them.