I nerfed Arcane Detonation further. Tell me what you think of the new version.

Arcane Detonation
Initiation Action: 1 immediate action
Range: 60ft.
Target: Your figment
Duration: Instantaneous

You charge your illusion with volatile arcane power just as your opponent destroys it, causing it to explode in a dazzling display of blue energy.

You may use this invocation when one of your figments have been destroyed. The illusion creates an explosion with a radius of 15ft. Anyone within this radius take 3d6 damage and is denied their Dexterity bonus to their AC until the beginning of their next round. Reflex save halves this damage. You and your allies are immune to this effect.

Surge 2+: For every 2 surge points spent, the blast damage is increased by +1d6 and the radius is increased by +5ft.