Beulah looks like a tall and attractive, but somewhat gaunt young woman, with pale skin, black eyes, and long black hair, which she normally styles into a half up bun with a pentacle hairpin. Her fingernails are naturally long and black, and she regularly applies dark purple lipstick.
On the surface, Beulah is the quintessential example of the traditional wicked witch: snobbish, haughty, demanding, domineering, self-centred, and very hot-tempered. She has great pride in her ancestry, and thus does not identify with humanity.
Perhaps because of her upbringing, the young witch-woman is quick to try and bully anyone she believes is beneath her, and she goes to great lengths to achieve retaliation for any wrong she has suffered.
However, Beulah is a nicer witch-woman than she seems. Her desperate quest to save her brother from Mordru is more than enough proof of that.
Beulah was born and grew up in Limbo Town, with her brother, Klarion, being born a few years later. From very young ages, the siblings constantly tortured each other, as Beulah bullied and tattled on Klarion on a regular basis, provoking the witch-boy into seeking retribution. It was not uncommon of the Bleak siblings to start vehement prank wars over petty offences every once in a while.
One day, the tension between the siblings boiled over, culminating in an arguement in which they disowned each other as brother and sister, and Klarion ran off to seek privacy on the outskirts of town.
Eventually, Beulah felt guilty, and went to find her brother to make amends. However, she found Klarion too late; he had already been found Mordru, a Lord of Chaos, who possessed the witch-boy and his powers, into being his new instrument.