Weird Arcana - Turjan's Inverted Largeness (New Spell)

I blame this one on Songs of the Dying Earth (yeah, it's a recommendation!).

Turjan’s Inverted Largeness

Transmutation

Level: Sorcerer/Wizard 3, Witch 3
Components: V, S, M (a pinch of powdered dragonfly wings)
Casting Time: 1 round
Range: Touch
Target: One corporeal Medium size creature (see text)

Duration: 1 minute/level
Saving Throw: Fortitude negates
Spell Resistance: Yes

This old spell causes instant diminution of the target until it stands barely a ½-foot tall (Tiny size). The target must be a corporeal creature of medium or bigger size. If used against creatures of Medium size, the dweomer affects one additional target for every four caster levels. The target suffers all the bonus, penalties and stat modifications resulted from being miniaturized to Tiny size.

For unknown reasons, Turjan’s inverted largeness carries two secondary effects. First, all targets acquire DR 5/cold iron, which may indicate that Turjan of Miir learned this dweomer from fey. Second (and most inexplicable) – the caster is incapable of killing any affected target, for the dweomer’s duration, unless he succeeds at a Will saving throw (DC 25). He also won’t allow any other creature to kill the targets. This side-effect – most sages explain – indicates without a doubt that Turjan learned the spell from fey (who else would enjoy such useless aspect?).

Turjan’s inverted largeness doesn’t work on constructs, fey or outsiders.

Turjan’s inverted largeness counters and dispels enlarge person. Targets under the effect of Turjan’s inverted largeness are immune to reduce person.

Turjan’s inverted largeness can be made permanent with a permanency spell.