Duke Sionn ("cee-on") has the picture-perfect look for the Goetia family, always maintaining his high standards for hygiene. Sionn always says he is clean and organized like he has nothing to hide, however, Saoirse says he’s more like a bleached bathroom after a crime scene. 

Sionn studied under Paimon for the first ten years of his life. He always had a telekinetic bond with his twin sister, Saoirse, however, the two rarely saw each other. Eventually Shax, not wanting to separate the twins any longer, took in Sionn for the betterment of his powers to which Paimon agreed. Sionn is the one being groomed for the throne while Saoirse has more leeway to do what she pleases. The twins had once promised each other that they would rule together when Paimon passes. However, Saoirse values her freedom from the Goetia family which makes Sionn feel disconnected from her. Sionn resents Paimon for forcing him into obedience to the throne as a result. Sionn has little contact with Stolas, his half-sibling because Paimon couldn’t keep it in his pants. It is possible Stolas could be the heir to the throne instead, but with his recent scandals involving an affair with an imp along with a divorce, that is unlikely.