Theocratic convert

As Humanity traveled the distant solar systems, they found many humanoid aliens.
The Theocrats, as Earth's  humanity discovered, had their primitive but expanding empire.
Some humans ventured into their empire, to explore and try to understand their worlds.. never to officially return.
 Many space faring humans have encountered the Theocrat converts, seeking to find new converts. Their phallic hats were standard to their religious clothing.
When the converts are in great numbers, humans and other aliens began to disappear.
Some human colony exo planets, forbid the Theocrats any residence.
Off world travel became bizarre, when there was Theocrat encounter. 

The Theocrats had their innocent persona. They also had their dangerous persona.