It's possible that:
* You are misremembering or misspelling the name of a religion. Perhaps you're thinking of a religion with a similar-sounding name.
* You've encountered a fictional religion in a book, movie, or game. Many fictional works create their own religions or spiritual systems.
* You're thinking of a specific person named Declan who may have founded or be associated with a particular religious belief system.
To help you find what you're looking for, could you provide more context? For example:
* Where did you encounter this term? (e.g., a book, a website, a conversation)
* Do you remember any details about this religion? (e.g., its beliefs, practices, founder)
With more information, I may be able to help you figure out what you're thinking of.