Alexa is a succubus witch. Made a Faustian bargain with the devil to slowly kill Bray with black magic, which he made himself vulnerable to by inadvertently inviting it in with his gimmick. Alexa pushed him further and further into it while he remained clueless to what she was really doing. In exchange she got to marry her childhood rockstar crush and beat cancer.
Liv tried the same thing with Bo when he was in shambles over Bray's death but he cast her out. Uncle Howdy is his bait to sniff out other succubi trying to do the same to others. He's playing with fire but personally vetted only his most trusted industry friends to be part of his group and protect him.
If Rey isn't looking out for Dom he will become yet another casualty sometime in the future.
