Those of you who've played the excellent "Planescape: Torment" game probably remember good old Dak'kon, and his sword of "karach." Chaosmatter from limbo. On looking over the new 3.5e DR rules, something clicked in my head when thinking about those special material DR's...and a substance who's existance is defined by the will of its wielder.
This is all in the shakey first stages of conceptualization, so any input is valued.
It would be heinously expensive, of course, using such exotic, extraplanar material. Right now I'm playing with adding up all the base costs for all the special materials that pierce DR (cold iron, adamantine, silver) and basing karach's cost as a multiple of the total.
I'm thinking that karach can't actually be enchanted with magic. It's too unstable. But a sufficient will (Wisdom) could cause it to be able to penetrate magic DR. That's iffy. A karach weapon is automatically chaotic-aligned, and cannot be altered by any means. Karach that somehow DOES get made non-chaotic (Wish, perhaps? Miracle?) is frozen in the form it's in...forevermore.
I'm playing with the following DC's...
DC 10 - Is effectively steel in substance.
DC 12 - Masterwork bonuses apply. Alter Weapon shape.
DC 14 - Can emulate alchemical silver, or mithril.
DC 16 - Can pierce x/magic DR.
DC 18 - Can emulate adamantine
DC 20 - Can emulate cold iron
The weapon can only be one form at a time. You can't have silver/adamantine mixes, for example. The only exception is that an item can stack MW bonus, magic DR, and any special material. Altering shape is generally only cosmetic, but can be used to increase or decrease weapon size by 1 increment.
A Wis check alters the item's form for 1 round, before it fades back to steel-equivalent. The user can take 10, but not 20. Thus, if the user's Wis is high enough to take 10, the weapon can be maintained in that form as long as the user is conscious.
Also considering adding higher DC's to transform the sword into elemental energy forms. Perhaps a monstrous DC to change it into pure force!
Thoughts?
This is all in the shakey first stages of conceptualization, so any input is valued.

It would be heinously expensive, of course, using such exotic, extraplanar material. Right now I'm playing with adding up all the base costs for all the special materials that pierce DR (cold iron, adamantine, silver) and basing karach's cost as a multiple of the total.
I'm thinking that karach can't actually be enchanted with magic. It's too unstable. But a sufficient will (Wisdom) could cause it to be able to penetrate magic DR. That's iffy. A karach weapon is automatically chaotic-aligned, and cannot be altered by any means. Karach that somehow DOES get made non-chaotic (Wish, perhaps? Miracle?) is frozen in the form it's in...forevermore.
I'm playing with the following DC's...
DC 10 - Is effectively steel in substance.
DC 12 - Masterwork bonuses apply. Alter Weapon shape.
DC 14 - Can emulate alchemical silver, or mithril.
DC 16 - Can pierce x/magic DR.
DC 18 - Can emulate adamantine
DC 20 - Can emulate cold iron
The weapon can only be one form at a time. You can't have silver/adamantine mixes, for example. The only exception is that an item can stack MW bonus, magic DR, and any special material. Altering shape is generally only cosmetic, but can be used to increase or decrease weapon size by 1 increment.
A Wis check alters the item's form for 1 round, before it fades back to steel-equivalent. The user can take 10, but not 20. Thus, if the user's Wis is high enough to take 10, the weapon can be maintained in that form as long as the user is conscious.
Also considering adding higher DC's to transform the sword into elemental energy forms. Perhaps a monstrous DC to change it into pure force!
Thoughts?