My E/N Build plz help

My Elemental/Necromancer Build
Primary Attributes:
Energy Storage
Fire
Death Magic

This is my opinion of the Ultimate Kamakazi Walking Time bomb, imho this might rock in gvg events plz help me perfect this.

Death Nova - Enchantment Spell
For 30 seconds, if target ally dies, Death Nova deals 26-85 damage to all nearby creatures.
5 2

Necrotic Traversal - Spell
Exploit target corpse, you teleport to that corpse's location and all nearby foes become poisoned for 5-17 seconds.
5 3/4

Putrid Explosion - Spell
Target corpse explodes, sending out a shockwave that deals 24-101 damage to each nearby creature.
10 1

Glyph of Lesser Energy - Glyph
Your next spell costs 15 less Energy to cast.

Inferno - Spell
Deal 15-99 fire damage to nearby enemies.
10 3/4 20

Flame Burst - Spell
All nearby foes are struck by jets of flame for 7-91 fire damage.
15 2 15

Lava Font - Spell
For 5 seconds, foes near this location are struck for 5-24 fire damage.
10 2 4

Phoenix - Spell
A fiery phoenix rises at your location, striking nearby foes for 7-91 fire damage, and flies out to your target, exploding on impact. This explosion strikes for an additional 15-75 fire damage.
15 3 25

Only weaknesses I see in this is that it'll take a while to cast all these spells.

By giving myslf death nova, I get full mana, then use that teleport spell to teleport onto a corpse near a group of enemies, poisoning them, I then start unleashing a barrage of AoEs. But my problem is a. Keeping them in the area which shouldn't be a problem if they all intend to attack me and b. The long casting times, Should I just do all the fast casting aoe's first then move on to the slower ones?

opinionz plz