A dawnspirit can communicate telepathically.
Telepathy 60 feet?
On their home plane, a dawnspirit's form is a ball of brilliant sunlight, much like a will-o-wisp, only brighter. When summoned to another plane, a dawnspirit acquires an aesthetically beautiful, but androgynous, form which glows with a pure, white light.
Borrow this?
Alternate Form (Su): A coure can assume the form of an incorporeal ball of light at will. This transformation counts as a standard action. In this form, the coure can be harmed only by other incorporeal creatures, +1 or better magic weapons, spells, spell-like abilities, and supernatural abilities. In this form, the coure has a 50% chance to ignore any damage from a corporeal source, except for force effects or attacks made with ghost touch weapons. A coure in this form can pass through solid objects, but not force effects, at will. While incorporeal, its attacks ignore natural armor, armor, and shields, but deflection bonuses and force effects work normally against them. In this form, a coure always moves silently and cannot be heard with Listen checks if it doesn't wish to be. While incorporeal, the coure sheds light as it wishes, providing illumination with any radius it wishes up to 30 feet. Changing the amount of light it sheds is a free action that the coure can perform once per round.
The pure light radiating from a dawnspirit causes fear in evil creatures who see the dawnspirit. Creatures of less than three hit dice automatically flee at their fastest movement rate until they are out of sight and for 1d3 rounds thereafter. Creatures of three or more hit dice save vs. spells or are paralyzed with fear for 1d4+1 rounds. Undead who make the saving throw still suffer a -2 "to hit" penalty when within 40 feet of the dawnspirit.
Here's an attempt at this ability...
Light of Purity (Su): A dawnspirit continuously raditates pure light to a radius of 40 feet that strikes terror into evil creatures. Evil creatures of less than 3 HD are immediately panicked (no save) for x rounds/minutes. Evil creatures with more than 3 Hit Dice must succeed on a DC X Will save or cower for x rounds. Undead creatures of any Hit Dice must succeed on a DC X Will save or be turned (as if affected by a turn undead attempt). The save DC is Charisma-based.
Once per day, a dawnspirit can utter a powerful holy word. This ability sometimes is called "the voice of the gods." Extra-planar evil creatures within 60 feet are automatically forced back to their home plane if not already on it. (This effect works even if the dawnspirit is not on its own home plane.) All other evil creatures within 60 feet are affected as if struck by a normal holy word. In addition, good creatures within 30 feet gain a +2 "to hit" and damage bonus for 1d4+1 rounds.
Voice of the Gods (Su): Once per day, a dawnspirit can utter a single word of powerful goodness. This functions as a holy word spell (caster level equals dawnspirit's Hit Dice). Additionally, all good creatures within 30 feet gain a +2 morale bonus on attack and damage rolls for 1d4+1 rounds. This is a sonic effect. The save DC is Charisma-based.
Ecology: Dawnspirits have no need to eat, sleep, or breathe. They can survive in the vacuum of space, in the depths of the ocean, or anywhere else in the universe, except the Negative Material plane, which they cannot enter. They have no enemies except evil creatures who hate them for their goodness.
Since outsiders normally have to breathe, we'll need a breathless ability, like this...
Breathless (Ex): Members of air races do not breathe, so they have immunity to drowning, suffocation, and attacks that require inhalation (such as some types of poison).
For the prohibition from the Negative Energy Plane, should we give them a vulnerability (+50%) to negative energy damage?