Most of the character relationships in this story are inspired by imaginations fueled by my hyperfixation on Alastor when I listen to a song. Some are my headcanons being moved to the AU, in case canon proves them wrong.
Alastor and Rosie: Rosie was the first person that Alastor got close to in hell. When she found him, he had barely just arrived in hell and struggling to control his new powers. She helped guide him through it. She witnessed him resummon his shadow and regain control over his powers. Alastor views her as somewhat of a mother figure. Several of the overlords that he killed were threats to Rosie and her cannibal colony. Rosie and her cannibals provide Alastor with a community that longed for but could not have while he was alive.
Alastor and Niffty: Niffty is like a daughter to Alastor. He found her when he was checking out the territory of an overlord that he was considering killing. When he found her, she was being treated as an ornament on a freezing, cold stage. He burned down the place when he freed her. He was her first bad boy.
Alastor and Husk: Husk was more than good at what he did before he met Alastor. He was on his way to becoming one of the most powerful overlords of hell. Husk had originally planned to win Alastor's soul to gain Alastor's power before things went downhill for him. Alastor was supposed to kill Husk but Niffty liked him. Alastor decided that he would make a good pet instead.
Alastor and Vox: Vox and Alastor were friends but Roo did not fully approve of their friendship. Vox over time became possessive over the attention he received from Alastor. It did not like it when Alastor would seemingly ignore him for periods, not realising that Alastor did it to protect him from the negative side effects of his power. Alastor played a big role in his rise to overlord status by providing him with protection. Their friendship ended when Vox accidentally took out his anger on Niffty. On some level, Alastor feels responsible for Vox turning out the way he did as it could be due to his own corrupting influence making Vox worse than he would have been.
Alastor and current overlords: Alastor is more powerful than all the current overlords but is only an overlord by technicality. He doesn't own that many souls (because he tends to eat them) and has no physical territory but is considered one based on his power. Other than Rosie, the other overlords are careful when speaking or dealing with Alastor as no one really knows what makes him decide to target an overlord. There have also been cases of overlords who spend too much time focusing on Alastor losing their minds and becoming horrible people after which they end up hunted by Alastor. Though none of them understand why, it is actually a side effect of him being a conduit for Roo. He respects Zestial for his skills as a gentlemanly overlord who deals in fear and Carmilla Carmine for being a good mother.
Alastor and Lilith: Lilith and Alastor have a deal. Alastor was originally loaned to Lilith by Roo as part of the agreement for a ceasefire between them. Before the arrival of Alastor, Lilith had been killing off the children of Roo who arrived in hell due to their highly destructive nature and tendency to go insane soon after arrival due to an inability to handle their new power. Alastor was saved from madness by his mother's voodoo protection. The seven-year disappearance was caused by Lilith going against her deal with Roo. This caused Roo to order Alastor to kill her. The fight ended with Lilith convincing Alastor to let her go with a promise that she would go where Roo couldn't reach her. In exchange, Alastor would help her watch over her daughter and would not do anything that could sabotage her escape. Roo punished Alastor for letting Lilith escape.
Alastor and Charlie: Alastor was freed from where Roo was keeping him by Charlie launching the hotel. The deal recognised her actions as her needing protection and freed him to fulfil his part of the deal. Before the fallout with Roo and Lilith, Alastor did not mind his contracts and even enjoyed it at times but at this point, he just wants out. While he didn't care much for her and found her ideas silly when they first met, he sees her as a good investment for his future freedom and survival.
Alastor and Lucifer: Between the information that he has about Lucifer from Lilith and Roo, Alastor despises Lucifer. He sees him as someone undeserving of the power that he has who spends his time on self-loathing while being incapable of owning up to his actions due to self-righteousness. He sees him as an irresponsible ruler, husband, and father.
Lucifer and Lilith: Lucifer knows about Lilith's agreement with Roo. Their disagreement over it is part of why they split up.
Alastor and Roo: The true holder of his contract. She took on the role of his mother after her death. However, she has been slowly losing his trust since he came to hell. She intends to use him to free herself from where she has been sealed. While he is an excellent conduit, she needs him to embrace his dark side even more and become stronger for her to escape. The few, weak morals that his mother managed to instil in him before her death are standing in the way.
