Ki-rin are like flying unicorns with shaggy, luminous gold hair; they are striking and majestic indeed. They are incredibly powerful creatures of lawful good.
It is easy to see how these things are essentially gods of the aerial kingdoms. If you throw out the Deities and Demigods extra-planar pantheons, as I have done, going for the "primitive, naturalist" religious concept, these things are pretty much at the top of the food chain in D&D.
I think a great way to incorporate these things into the campaign would be as the "distant benefactor". Imagine a Ki-rin living on a nearby mountain top... He tends to keep the whole area cleared of evil monsters... Naturally, humans would tend to bring gifts and sacrifices of thanksgiving to his lair on that mountain top...
But then, one day, after an epic nighttime battle, with flashing lights and explosions viewable for miles around, the Ki-rin seems to be gone... Dark evil begins to stalk the land... Heroes are called to investigate the Ki-rin's mountain lair...
Or, suppose this strange, golden, flying unicorn begins to make new appearances in the area... But so are demons and devils... The humanoids and beast-men are on the move... The dark forces are gathering, and something portentous seems to be gathering momentum...
The Ki-rin lands in the middle of the town square amidst a huge lighting storm... He calls for the bravest and most valorous warriors, priests, and magicians, to ride forth immediately with him to stem the tide against the ancient foe....
Whatever it is, the presence of a Ki-rin signals something big, very big.
Magic resistance: 90%
Psionic Ability: 130-200
4 major disciplines (choose from): etherealness, astral travel, body control (hostile environs), energy control, mind bar, molecular manipulation, molecular rearrangement, telekinesis, teleportation
6 minor disciples (choose from): cell adjustment, clairaudience, clairvoyance, detection of good/evil, detection of magic, invisibility, molecular agitation, object reading, precognition, sensitivity to psychic impressions
Spell use (18th level), per day:
9th level - 1x, 8th - 2x, 7th - 3x, 6th - 4x, 5th - 5, 4th - 6, 3rd - 7, 2nd - 8, 1st - 9 (note: sky/air related spells at double strength)
1x per day:
Create food, water, and Ki-rin beer, 2-24 people
create minor goods
create metal goods
create programmed illusion
assume gaseous form