About

Hildegarde (ヒルデガルダ Hirudegaruda?)
Voiced by: Kana Ueda (VOMIC), Shizuka Itō (OVA, Anime)
First appearance: One-shot
Preferring to be called by a shorter name, Hilda is a demon maid who helps Oga take care of Beelzebub IV. She reveres the Devil, or Demon Lord, and feels that it is a great honour to be chosen as the child's "Mother", or caretaker, by the Demon Lord. Her most characteristic features include her Gothic Lolita appearance and (as pointed out by Oga's mother) "great big knockers." Hilda is also described as a bombshell, and her right eye - the left has not been shown so far and is always hidden behind her hair - is green. She rides a flying, leathery creature known as an AK-Baba[15] as transportation and owns an umbrella which conceals a sword in the handle.[16] Oga's family is under the impression that Oga and Hilda had sex and that Beelzebub was the result.[17] After the fight with Toujou she seems to accepts Oga to raise baby Beel and becomes warmer towards him.
Despite being blunt and cold most of the time she has been shown to have a kinder side that comes out from time to time, often at the surprise and/or disbelief of the other characters.[18] Being a demon herself she is quite knowledgeable about the demon world, being able to successfully navigate Oga and company through Vlad's Haunt. She takes being Beel's mother quite seriously and even goes as far as to state that it was the only reason for her existence. As a fighter she is quite skilled. Her skills gained her the nickname "Oga Bride" at Ishiyama, as she dispatches her enemies in a similar manner to Oga (e.g., shoving her opponents' heads into walls). In the anime she has developed an interest in watching soap opera, much to Oga's disbelief. Her name comes from the Old High German name "Hildegard" meaning Hild (=war or battle) and Gard (=protection) and means "protecting battle-maid".
Hilda and Oga share a love-hate relationship, most often bordering on the hate side. Hilda often looks down on him and never hesitates to mock him. In turn, he finds her cold and manipulative personality annoying. However, it is shown on rare occasions that they do care about each other work extremely well together in a fight.
She was given the responsibility as the mother by the demon lord which she takes seriously and with the time her feelings for Beelzebub have grown far beyond the resposiblity to watch over him and is shown to deeply care for his well being, becoming infuriated at her lack of ability to protect him when attacked.
Initially in the manga, Hilda was probably the most powerful of the series protagonists, as she was able to, for a short time, fight with Saotome while Oga, Tojou, and Izuma were taken out instantly by the teacher. When she becomes serious in a fight she'll become surrounded by a pure black aura, which she then channels into her sword for a powerful attack. It is implied that, as Beel, her full-fledged powers are much greater than what she is able to show in the human world, but she would need a human contractor to access them. She is considered to be the very elite among demon wet nurses, and is able to defeat Lord En's three maids single-handedly (see below). More recently, though,[19] Oga may have surpassed her by learning to use Beel's powers.