I'm astounded this one hasn't been rec'd yet.

Title: He Says He Is An Experimental Theologian

Fandom: Welcome to Night Vale / His Dark Materials - Philip Pullman fusion
Pairing: Carlos/Cecil Palmer
Categories: Alternate Universe - Daemons
Length: 181,998 words
Warnings: the usual WtNV warnings ("Canon-Typical Violence"); Re-Education; For Science!; Culture Shock; Post-Traumatic Stress

Author on LJ AO3: SailorPtah
Author Website: see AO3 profile for links

Summary:

Ever since Carlos was little, he and his daemon have been fans of Dr. Lyra Belacqua. Both as the most groundbreaking experimental theologian of the 20th century, and as the heroine of dozens of fantasy-adventure children's stories (based very loosely on her own mysterious childhood).

But Lyra's true legacy is still bigger than Carlos ever imagined...until he took a team of scholars to study Rusakov particles in the most theologically interesting community in Hispania Nova. Now his own day-to-day life is full of things like angels, witches, hooded spectres, portals between worlds, vague yet menacing branches of the Magisterium, and a man who walks around without his daemon and can read an alethiometer as easily as a stop sign.

He Says He Is An Experimental Theologian