When the Kithain turn from their creator to serve the Famorians they change into vicious and nightmarish version of themselves. This causes their Seelie Legacy to become inverted. What ever the Quest and Ban of the Legacy was it now does the opposite.
When the Kithain become corrupt they turn into new Kiths, the technical term for them is Thallain. Were as the fear Sluagha or Red Caps install is useful and teaches caution, Thallain inspire fear that promotes selfishness and instinctual promoting action without thought.
Aithu: Dangerous Strangers
Original Kith: Eshu
Beasties: Fearsome Monsters
Original Kith: Pooka
Boggarts: Greed's Motivation
Original Kith: Boggans
Bogies: Dependent's Loathing
Original Kith: Slaugha
Ganconer: Painful Desire
Original Kith: Satyrs
Goblins: Treacherous Technology
Original Kith: Nockers
Ogre: Stupid Submission
Original Kith: Trolls
Spriggans: Tragic Trickery
Original Kith: Piskies
Tylwyth Teg: Terrible Beauty
Original Kith: Sidhe
the fae become pale, if their hair was black it becomes light blue, red hair to strawberry blonde, blonde hair to pale blonde. Unlike most Thallain the Sidhe Thallain become more beautiful, but so beautiful that they have become alien. No longer attractive more like a painting or a statue.