This spell functions like shadow conjuration, except that it mimics conjuration spells of 8th level or lower. The illusory conjurations created deal four-fifths (80%) damage to nonbelievers, and nondamaging effects are 80% likely to work against nonbelievers.
This spell functions like shadow conjuration, except that it duplicates any sorcerer or wizard conjuration (summoning) or conjuration (creation) spell of 6th level or lower. The illusory conjurations created deal three-fifths (60%) damage to nonbelievers, and nondamaging effects are 60% likely to work against nonbelievers.
So, Shades says it copies Shadow Conjuration, but unlike Greater Shadow Conjuration, it lacks the phrasing that would restrict it to Wizard spells of the summoning or creation subschools.
Does this mean it can copy any conjuration spell, even those from other class lists, so long as they're 8th level or lower? (Such as Greater Planar Ally, or Heal?)
We don't have to discuss all the other ambiguities with shades, like what happens if you use it to duplicate Create Demiplane or Trap the Soul, just what spells are implied by this difference in wording.
The fact that it says "functions like shadow conjuration" means to me that it is still restricted to wizard/sorcerer spells. The "except" that comes next is just in relation to the level of spells that it can duplicate.
Wow! Great resource! Thanks Claxon!
I can't take credit for it. I'm a big fan of Zenith Games The Comprehensive Guide to Pathfinder Guides