Epic: Grey Goo with Destruction

[DemonSlayer]

Hey people,

So, after toying with the concept of a self-replicating spell, I decided to add something to it. Now, this spell doesn't simply conjure an adamantine cube like my last spell did. This one also casts a destruction effect at a target specified by the original caster. So what we have is this; either the target succeeds on a Fortitude save (DC "pretty damn high") each round, or suffers 20d6 of damage (10d6 if it succeeds).
It does leave me with a few question;

1) The cube is a 20ft. adamantine, 20 cubic ft. cube. Could anything break that in one single round (before it had time to reproduce)?
2) Am I better off using a slay seed rather than a destruction seed? Slay has that nice "kill it outright"-effect, which is more reliable than 20d6 of damage, but on the other hand anything immune to death effects (Tarrasque) and anything not really alive (undead) are immune to it.

So, any thoughts, opinions? Anyway here's the spell;



Pendyn's Repetitive Destruction
Conjuration [Creation]
Spellcraft DC: 38
Components: V, S, XP
Range: 0 ft.
Duration: 24 hours
Saving Throw: None; Fortitude halves (see text)
Spell Resistance: No; Yes (see text)
To Develop: 342.000 gold, 7 days, 13.680 XP, Seeds: Conjure (DC 21), Animate (DC 25), Conjure (DC 21), Animate (DC 25), Destroy (DC 29), Destroy (DC 29). Factors: Quickened reproduce (+28), One-action destroy (+20), one-action grant destruction (+20), one-action spell (+20). Mitigating factors: Burn 20.000 XP (-200)

At the time of casting, choose one creature or 10-ft cube of unliving material, which may be part of a bigger whole. You conjure an adamantine cube, 20 cubic feet in volume, which is animated as part of the spell. The cube also gains two spell-like abilities.
The first spell-like ability is a one-round action and deals 20d6 damage against the selected target. A succesful fortitude save halves this damage, and spell resistance applies.
The second spell-like ability reproduces this spell, creating another animated, adamantine cube, 20 cubic feet in volume, which has the same two spell-like abilities. This new cube will choose the same target as the previous cube. If no target is left, then the new cube will not cast the destruction effect, nor the reproduction effect.
Cubes remain in existence for 24 hours and vanish afterwards.
XP Cost: 20.000

[Claudius Maximus]

You realize that Backlash damage is per round, right? And one flaw I see with this spell is the possibility of the target simply escaping.

[DemonSlayer]

Good point on backlash damage being per round. Fortunately, even if I drop the backlash damage the spell DC will only be 38 instead of 28. So that's manageable...

The target could try to escape, which would basically end the spell. Note, however, that the destruction effect has a range of 12.000 ft (I should specify that).

However even if he escapes using teleport or planeshift or whatever, he's still out of the fight. And that's a good thing .

[Claudius Maximus]

But do you really want that at epic level play? You've wasted an epic spell slot and 20k xp and they're out a 5th or 7th level spell (or one use of a SLA). I think it would be more effective to just deal 100d20 damage or something.

[DemonSlayer]

So, maybe the slay seed would be better? If he saves, then he'd only take 3d6+20 damage, and he'd probably not run from that. If he failes his save, well, then he's a pile of dust.
But it would be a shame if the spell didn't work against non-living material...

[woodenbandman]

Pretty cool self-reproducing effect. Worth 20k XP? No.

[Set]

I always wanted to make a contagious cure spell. Cast it in a plague ridden city, and watch it hop from person to person, stripping them of plague (and any other pesky disease) as it spreads.

Chain Resurrection would be a nightmare.

"Sire, your ancestors are at the gate, and they don't like the way you're running the kingdom." "What?" "They also brought their armies. All of them. Going back 750 years..."