Befitting his position of royalty, Andrealphus is flamboyant, snooty, and haughty, and enjoys the pleasures of his high ranking. Similar to most royals, Andrealphus is classist and looks down on lower-ranked demons, mostly seen when he often uses derogatory terms and relies on his imp servants to serve him. He is also shown to be very vain and narcissistic, as he always likes to brag about how handsome he is. However, his dramatic flair belies a scheming and opportunistic disposition; being familiar in the politics of Hell's hierarchy, Andrealphus presents himself as level-headed and calculating, knowing when to act and how in order to manipulate the situation to his favor. As such, he can be quite cold-hearted and remorseless, eager to trump on others for his own benefits.

Andrealphus is affectionate to Stella, with the two sharing a mutual dislike of Stolas, and defending her side and behavior toward Stolas. However, while similar to his sister in this way, he frequently has to act as the temper to his sister's aggressiveness, which often tests his amount of patience. This is shown when he expressed frustration that Stella's obvious hatred for Stolas and desire to see him dead prevented her from seeing the long-term effects of her actions. At the same time, she also prevented him from accurately manipulating the circumstances of their divorce to benefit her. Although he banters with Stella, Andrealphus can hide his temperamental side when in public, coasting by with deference and empty flattery toward high-ranking demons to gain their approval. Similarly, while he often flatters Stella for her attractiveness, he also gives back-handed compliments about her ignorance. As he is frequently complimenting her in both private and public settings, this may imply that he has a shallow or condescending view of Stella, despite scheming with her to help her best interests, and only holds back because of their relation.

Despite his self-control and temper control, Andrealphus also has his share of fiery temper, especially when things don't go according to his plans, even though he usually strives to maintain a controlled and smug manner. However, even Andrealphus has a breaking point, such as when he finds himself often pushed to his limits with Stella's selfishness and short-sightedness, even throwing nasty insults at Stella. Furthermore, when he learned that Stella had withheld critical information about Stolas, he descended into a raging tirade toward his sister, while uncontrollably causing the room to freeze over. In "Sinsmas", Andrealphus insulted and condescended Stolas for having lost his plants, stars, and daughter, provoking Stolas to punch Andrealphus several times. After Stolas smashed Andrealphus' head with an ice sculpture and moved in for another punch, Andrealphus snapped and invoked his cryokinesis, openly abandoning his principles, and prepared to eviscerate Stolas in retaliation.