I have one.
Sacred Abjurer
Primary Skills: Mysticism, Restoration, Destruction
Major Skills: Thaumaturgy, Alteration, Illusion
Minor Skills: Etiquette, Blunt Weapon, Dodging, Running. Medical, Stealth
Advantages: Bonus to hit undead, Bonus to hit daedra, Increased magery 3x int, Regen health in water, spell absorption in darkness
Disadvantages: no armor, damage from holy places, darkness-powered magery
I got the idea for the "abjurer" part from the D&D magic school of abjuration, and abjuration specialists are abjurers, and the word abjure means to avoid, shun, renounce or repudiate...in D&D abjuration magic dealt mainly with protection, prevention and banishment.
In game, I tend to name all my custom spells names that would make sense for holy spells or divine rituals, and tailor spells and gear to be anti-undead, and anytime I enchant misc. items I try to have them be holy objects, like holy water or something like it. Also I generally try to do quests more for temples and less for mages guilds, since this is more a priestly character than a wizardly character.
I always thought some of the advantages were a little strange, and decided to make Sacred Abjurers regen health in water, thinking of the whole baptism idea and cleansing by water.
My explanation for the class' disadvantages is that the priest has to become somewhat like the undead to fight them most effectively, and that the priest spends so much time in evil places trying to destroy undead and daedra that a little of the places' essence gets into him/her.