Your shadowy illusions are more potent.

Prerequisite(s): Spell Focus (illusion).

Benefit(s): When casting greater shadow conjuration, greater shadow evocation, shadow conjuration, or shadow evocation (and, at the GM's discretion, any similar spell with the shadow descriptor that mimics a spell of another school), that spell is 20% more real then normal.

Level Increase: +1 (a solid shadows spell uses up a spell slot 1 level higher than the spell's actual level.)