Purging flames skill gem idea

Purging flames
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Spell, Aoe, fire
Level: 20(max)
Mana cost: 270
Cast time: 1.40 sec
Critical strike chance: 5.00%
Effectiveness of added damage: 115%
Qaulity +1%
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Requires level 67: 155 int
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Cast to create to medium balls of that you combine into a big ball of flame that you slam on the ground creating a massive 360° wave of cascading flame dealing high damage to enemies caught within. Cannot be supported by spell echo, cannot be supported by spell cascade
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Deales 1% extra fire damage per 1% qaulity
Deals 880 to 1250 fire damage
80% more damage against ignited enemies
Flame wave cascades 3 times
Cannot ignite enemies
Creates burning ground
Burning ground deale 150 to 350 fire damage per second

Whats your opinions exiles?