Chaotic Skyflare Diamond
Stormy Sky Sapphire x 2(or 3)
Hit gem if you're below cap
Then stack strength gems
Helm: Arcanum of Torment/ Arcanum of Triumph
Shoudlers: Greater Inscription of the Axe/ Inscription of Triumph
Cloak: Spell Piercing
Chest: Super or Powerful Stats/ Exceptional Resilience
Wrist: Greater Assault
Waist: Eternal Belt Buckle
Legs: Icescale Leg Armor
2 Hander: Rune of the Fallen Crusader or Cinderglacier
Weapon enchant is personal preference. Fallen crusader procs more and allows for a high steady output of damage. Cinderglacier offers higher burst potential.
Some players prefer Scourge Strike over Disease Glyph. It depends on how well you think they will keep your diseases up effectively.
Some players also pick up Chains of ice glyph. It adds a little extra damage but overall doesn't really add to your burst.