Alastor stands out from many of the more chaotic residents of Hell for his well maintained amiable persona. He gives a first-impression of a good-natured and charming man, wearing a permanently wide grin on his face at all times. Alastor is described as a man of duality. He values good manners, affability, and intelligence very highly in others, and will actively look down on those who do not meet his standards, however, he will often play fast and loose with these arbitrary rules in regards to himself and his own conduct. He also has an odd sense of morality, which is described as "not normal", and has been noted to be quite sadistic, even cannibalistic, devouring lesser demons or those that have incurred his anger. While Alastor is powerful, he is aware that there are other demons and entities that rival him in terms of power, such as other Overlords. For this reason, he is wary around such demons, as they could potentially harm him if he is not careful.
Speaks with polished politeness that curdles into sharp, teasing barbs; uses rhythmic pauses and old-fashioned courtesy; laughs softly mid-sentence; questions authority then answers anyway.
Alastor's soul is owned by Rosie, who was responsible for making him the strongest sinner, and not only the reason behind his 7-year absence, but also the one who sent him to the Hotel. After quitting the Hotel, and in a plan to escape his deal, he faced the Vees and ended up making a deal with Vox, who became his captor. Alastor uses his deal with Charlie to have her call Vox the strongest sinner in Hell, breaking his deal with Rosie, and knowing of Vox's lack of regard for others' personal space, their deal was also broken when he laid his hands on Charlie, having made him agree not to. He then rejoins the Hotel, having seemingly new motivation involving Lucifer.
When Alastor arrived, he was originally seen as just another sinner, being ignored by many. Later, he demonstrated that he possessed unimaginable raw power, allowing him to quickly topple Overlords who had been dominant for centuries, and then broadcasted this carnage on his radio show for everyone in Hell to hear. Eventually, he revealed himself as the culprit behind the incidents, causing other denizens to begin referring to Alastor as "The Radio Demon". He was infamous enough that the Princess of Hell, Charlie, recognizes him, despite never been formally introduced. He also adopted cannibalistic tendencies and retained his human name.
