I played an Illumian bard and had a good time. Don't bother if you're not planning on multi-classing. Their racial abilities only come to the fore when they have more than one class.
The biggest problem is that they have (as written) these glowing symbols floating around their heads. If you change those to something else like I did, they are a pretty good race.
I wouldn't do that. It's a huge part of the flavor of the race, and they can make them disappear themselves if they don't want them around. They don't gain the benfits while they're hidden, but will easily pass as a vanilla human.
Racial traits summarised:
- The sigils grant candle light, and as mentioned can be hidden.
- If their hit die is equal to or higher than a glyph type spell or trap's caster level they're immune. If their HD is lower they have a -4 to saves
- At first level they get one power sigil. Each of the power sigils ties to a stat and gives +1 to skills and checks for that stat.
- When they reach 2nd level in any class they get another one.
- If they have two sigils, those combine into a power word. The power words have various effects like using your strength score to determine bonus spells per day, spend a turn attempt to add wisdom to damage, an ability similar to the divine metamagic feat, use Dex for bonus spells, leave a spell slot unfilled to gain insight to attacks and damage, and more.
- +2 saves vs. shadow spells
- always literate, speak language is always a class skill
- when they die their sigils speak for a round
