SHAPING-MIRROR
The mirror shaping rune allows illusionists to cast mirror images of other spells that they normally cannot cast. Usually only damage spells can be mirrored in this fashion.
The illusionist must still know the runes that form the spell that they are attempting to mirror. Furthermore, illusionists cannot mirror spells that are higher than their level. Spell levels are determined by averaging the earliest levels at which all the casters get the spell. For example, if druids got hellfire at 123, and mages got it at 112, and no other classes got it, illusionists would be able to mirror the spell at level (112+123)/2 or level 118.
Victims of a mirrored spell also get to make a Will save modified by intelligence to see through the illusionary spell. Since illusions play on the mind, it is harder to establish an illusion in less intelligent brains. Really intelligent creatures are also more likely to notice imperfections in the illusion. Mirrored spells work best against average-intelligence creatures. Creatures that make this save see through the spell and take no damage.
Creatures that fail the save are hit by the spell as if it were the real thing with the exception that 50% of the damage will be of element colour. For example, if an illusionist cast a mirrored balefire spell at a monster, the monster would take normal balefire damage but 50% of the damage would be fire (from balefire) and 50% would be colour.