Would this build be a good way to build an illusionist character(for PFS, so only to level 12).
Gnome Oracle (Heavens) 5/Veiled Illusionist 7
Blackened (PFS Legal?) or Haunted Cursed
Strength 5 Charisma 20
Traits:
Fast Talker
Magical Lineage: Color Spray for Persistent Spell?
Feats: Spell Focus/Greater Spell Focus (Illusion), Persistent Spell?
Obviously this build is very synergistic against anything vulnerable to illusions and especially mind-affecting spells.
The question is can this character contribute adequately against other types of monsters? The Veiled Illusionist adds an extra illusion spell at each PRC level, so Shadow Conjuration and Shadow Evocation help in this regard. If all Gnome Favored Class Bonuses are used on Curses, this build still gets Telekinesis or Wall of Fire at level 10. Which spells should be taken on the oracle side to fill in the gaps in the illusion strategy?
You're going to be up in the enemies' face given the use of color spray. You want freedom of movement once it becomes available to avoid being caught there by grapplers. Otherwise buffs and dispel magic sound good.
PFS parties tends to be long on beatsticks, and Wall of Fire, IME, doesn't do the job of a wall spell. So I'd take Haunted.
Undead are common enough that the Threnodic Spell metamagic feat may be worth it, even with the Spell Focus (Necromancy) feat tax.
There's also Spell Focus (enchantment) -> Coaxing Spell (from Dungeoneer's Handbook) for vermin and oozes, but those tend to be less common.
I recommend it as a metamagic rod since you can get by with a lesser.