Daemonism is a religion that revolves around the worship of, surprisingly, daemons. Followers practice a form of magic called chaos magic, which flows out of the daemonic realm. While it is powerful, it causes side effects to the user. Chaos magic causes mutations in the individual, making them more daemonic in appearance. The more they use, the heavier these mutations are. Users become more powerful as their bodies become more capable of using and containing chaos magic.
There is a faster way to power however. By summoning a daemon from their reality,, one can bind with them and create a new entity called a daemon host. These individuals are semi-gods among men, who can use chaos magic effortlessly. The ritual is dangerous and failure would result in the individuals soul being consumed. Success however will lead to UNLIMITED POWAH!!!
The problem is that those who want a chance of succeding during the ritual must be free of corruption. Those who have gone down the path of using a lot of chaos magic and have become heavily mutated will fail in the process. Therefore, only newer imitates who haven't utilized so much magic and haven't become mutated are viable candidates.
This is strange because it seems counterintuitive. Those who have utilized magic and have begun changing would seem the most likely to succeed in binding a daemon to themselves, as the entity is made up entirely of chaos energies and the individual possesses a ton of it. But the most powerful mages are the most likely to fail. Why would this be the case ?