Challenge: "Manichaean" Bulgaria

By Manichaean, I mean one of the medieval heresies gnostic heresies that were called Manichaean by it's opponents.

How can we get the state religion of Bulgaria during the middle ages to be one of the various gnostic sects that arose during this time period? I'm thinking mainly Paulicianism and Bogomilism here.

Also, what would the effects be on history?

The Byzantines and Rome aren't going to tolerate such heretics, so something would have to shield them to develop. If Byzantium collapses earlier and the muslims occupy Bulgaria could allow for Bogomils to flourish. Although if I remember correctly, the Bosniaks were also considered heretical christians, and they converted to Islam when the Ottoman's invaded.

This is one of the topics I used to know a lot about and occasionally have brought up in other threads. Let's see if I can dredge up anything relevant...

Paulician success
Paulicians convert Boris I

Huh, I was thinking of something similar to the first one. Something along the lines of: Chrysocheir allies with Boris, Chrysocheir and Boris invade the Empire, they are defeated and most of the Paulicians flee to Bulgaria.