Al/Relationships

Priscilla Barielle
Although he was bribed to be with her, over time Aldebaran realized that he really wanted to protect her, and although he is often beaten by Priscilla, he continues to accompany her. He dislikes it when Priscilla uses his full name, getting unreasonably angry and snapping back at her. Despite that, he's perfectly willing to give his life for her safety and well-being as shown when he died 1000 times trying to convince her not to go to Vollachia and risk her safety. In the end, he gave in and is currently accompanying her to the Empire.

Schult
Schult and Al both care about each other, since Aldebaran suffers a lot when Priscilla hurts him.

Rem and Ram
Al seems to be acquainted with Ram as he mistook Rem for her older sister during the third failed loop of Arc 3. Throughout their following short interaction, Al expressed his shock at realizing he was speaking with Ram's sister, indicating he only knew of her existence and not of Rem's. Soon after, he turned extremely hostile though managing to contain himself in mere seconds. After Rem and Subaru departed from Priscilla's manor, Al seemed to have gained somewhat of a grasp on the situation; a situation that made him want to vomit.

Rem seems to sense something negative towards her from Al's gaze.

Arakiya
Al and Arakiya crossed paths roughly 7 years before the start of the main story, during the gladiator upbringing that took place on the gladiator island Al was situated at. Upon first meeting Al, Arakiya expressed her interest in his face, stating it "wasn't bad". The two were forced to form a short alliance in order to fight another gladiator by the name of Hornet, who was guarding the drawbridge which connected the island with the mainland and was preventing the Imperial Army from entering the island and subduing the uprising. After their fight, Al expressed his immense happiness for finally being able to save a beautiful silver haired girl, as he once already had the chance to do so, but failed.

Satella
It is heavily implied that Al knows Satella personally. In Sunlight on the Water, Al encounters an illusion of a shadowy figure wearing a shadowy dress, which Al was unable to bring himself to harm even though he tried some 100,000,000 million times. Unable to do anything, he was gripped with fear, and tried to retreat as it attempted to touch him lovingly with its fingers. Fortunately, Priscilla destroyed it with her Yang Sword, yet this caused him to be filled with rage, though she easily dealt with him by smacking his helmet with her sword. Although he was still scared somewhat, he was relieved that the shadowy figure was fake.

In The Crimson Countess and the Gladiator, Al states that at some point in his life, a beautiful silver haired girl appeared before him when he was about to die. He also states that silver hair brings him bad memories about how a "trash, stupid useless person he is" due to how he failed to save the one he cherishes the most.