I deleted Demons 1 and 2 and focusing all my attention onto this one. Would be far less popular. But it's better organized. And anyway, due to that lets give a long backstory drop. Interrupts from the story but is very important in the long run.
In this universe there are two kinds of demons. Evil ones who come from Hell and are exactly what you think they are. And others, who are only demons in name. They live in another dimension but they are guardian angels of earth. Our story focuses on two of the latter kind, Verona and Liz. And mother and daughter duo who are assumably amongst the leaders, it's never detailed exactly what rank or importance they are amongst their kind, but they are clearly heroes. Even if not always the nicest.
Many years ago, long before the story Verona met Ogdan, a large black dragon claiming that he carries the cure for his dying village but it can only be given if he has a child. Feeling sympathy, Verona has sex with him. But she soon finds out the villagers aren't ill. They're poisoned.. By Ogden. And he simply wanted a child for some kinda power trip. Plus he's physically abusive to Verona, who quickly flees with baby Liz, so Ogdan won't be her father.
Ogden, the crazy bastard he is, goes on a killing spree. Killing everyone of his own village. And staged it as Verona having left them to die. Making Verona wanted of most dragon villages.
Many months later V is saved from a Hell Demon by a powerful vampire, Alucard of Hellsing. Hellsing Inc disbanded after Interga's passing, Seras moved to San Andreas to become a police officer again. Which is a story in itself, one already explored. Alucard meanwhile wondered around aimlessly, eventually finding Verona who gave his life purpose again by giving him a job as her protector. But over time the two become full on lovers. Being actually older than Verona, though not much. Alucard considers himself a father figure to Liz. Who doesn't need one, but she humours the idea and goes along with it. Often calling him 'dad'.
Meanwhile in another timeline we meet Rick Sanshez. An alcoholic inventor and portal traveler who destoried an army of all the Rick's across the universe. Long story.. But this alerts the attention of evil Verona, Betty, and evil Liz, Katherine. Who in this timeline aren't protectors, but universal terrorists who didn't like Sanshez taking out their known allies. As punishment they straight up murder Rick's family and for some reason destory the entire planet altogether.
Rick portals into this timeline. Kills the other Rick and basically acts like nothing happened. Except when Liz wonders by and he flips the hell out, trying to murder her and is knocked unconscious basically. Despite the hostility Liz sends Rick to work for him and Verona. Where he's eventually called on a mission in San Andreas. As a hell demon wondered over and infected Pinkie Lancer.
We know the story from there. But basically, during the rest of the crazy stuff happening. Betty and Katherine followed Rick here and now are looking to groom Carly to join them.