My first epic spell

[las]

Thotin's Devastation Blast
Transmutation
Spellcraft DC: 115
Components: XP
Casting Time: 1 action
Range: 12,000 ft.
Area; 80-ft.-radius spread
Duration: Instantaneous
Saving Throw: Fortitude half
Spell Resistance: Yes
To Develop: 1,035,000 gp; 21 days; 41,400 XP. Seed: Destroy (DC 29). Factors: increase damage to 100d6 (+160 DC), increase damage die by 4 steps (+40 DC), 1 action casting time (+20 DC), No verbal component (+2 DC), No somatic component (+2 DC), Change from target to area (+10 DC), increase area to 80-ft.-radius spread (+12 DC). Mitigating factors: 60d6 backlash (-60 DC), burn 10,000 XP (-100 DC).

When Thotin's Devastation Blast in invoked, the targeted area is blasted with pur destructive Force. All creatures and objects in the area suffer 100d20 points of damage. Creatures and objects slain or destroyed by this blast are reduced to a fine powder; the typical remains of a region blasted by this spell resembles a large dusty crater.
The caster suffers 60d6 points of backlash damage when this spell is cast.
XP Cost: 10,000 XP.

What do you think

 

[Angcuru]

2 things.

clarify wether the radius is from a point designated by the caster or if the caster himself is at the center.

it would take one REALLY buff mage to cast that spell.

 

[las]

if it has a range wich this does its placed by the caster.

 

[Cloudgatherer]

Now all you need is a 100th level caster and your set... well maybe a 90th....

 

[CRGreathouse]

Not bad -- 500 damage to an enemy party (double if they fail their save), unless they have SR. I'd throw in a bit of SR buff, even if it was at the cost of some damage; with a DC that high, it's probably worthwhile.