Ramble post about Alucard/Atom/Anderson's relationship!
Couldn't think of a fun way to illustrate this, so I'll just talk about it in text form! I'll put it under a read more because I think this will turn out to be long...
In basic sense, they are a polyship. They all have different relationships with each other. Plus Alucard still has relationships with MANY others in my AU (mostly because it is a shared AU with a friend of mine!) Anyways, I'll go through each one:
Atom and Anderson — Mentors to each other/Strained Friendship
Atom and Anderson start real rocky. Atom is non-religious and open-minded and Anderson is very religious and closed-minded about MANY things. Plus sharing Atom's body makes Anderson more hostile then he would like to be. He's very closed off, especially in the beginning. His issues only come out if Atom reads between the lines - thankfully Atom is good at understanding people.
Much later into the relationship, once they get comfortable with the body issue, Atom and Anderson develop more of a mentor/mentee relationship. Atom helps Anderson experience things outside of his fixations and Anderson helps Atom with exorcisms, training, and swordplay.
Once they find some common ground their relationship grows closer, but not by much. Atom isn't that physically attracted to him (other then height), but watching Alucard and Anderson interact is very fun for them. Anderson thinks Atom is pretty cute and finds himself getting more protective the longer they stick together.
When Atom becomes a dhampir and Anderson becomes their familiar, their relationship gets MUCH better. Since Anderson can actually separate from Atom with a physical form. By then, Anderson and Alucard are much closer and it makes Anderson bolder with Atom.
Anderson eventually starts to pull Atom into more things with Alucard, knowing they want to be apart of it but aren't courageous enough to ask. Atom is a flustered mess.
Anderson also has the plus that he can literally read every thought and see Atom's memories... such an unfair advantage.
Atom and Alucard — Close friends with benefits
Because of Anderson's previous affection for Alucard, Atom isn't tense around Alucard to begin with. Their body responds openly to him already much to Atom's dismay and confusion. But overall, they get along pretty okay even to start. Atom doesn't take any of his shit and Alucard teases the hell out of them.
It doesn't take very long for Alucard to be flirty, as he is himself, which Atom doesn't mind. They ARE annoyed by him. But annoyed because they think he's hot in most of his forms, and his way of dealing with Atom is much to their liking.
At their max annoyance, Atom does fight with him actively. They really fucking hate him sometimes and show that they won't be stepped on. Alucard loves that energy of course. Fire and oil, really.
Body wise, they are very compatible. Atom hates/loves how well Alucard can spin them around his finger. Sometimes he crosses lines, but Atom let's him know what's up.
Emotionally, Atom cannot match Alucard's passion and doesn't give him that type of attention. Atom is aromantic and Alucard craves that closeness. Despite that, later on in their relationship, Atom is happy to just talk to him and Alucard appreciates it. Atom is very good at calming people down. Alucard is also good at hyping Atom up when they need it.
They end up pretty chill over time, especially when Atom becomes a dhampir and can give him a proper fight. They watch a lot of movies together and explore haunted locations.
Anderson and Alucard — Dating(?) emotionally and fighting physically
Overall, in this AU, I assume that Alucard and Anderson had some form of relationship before the climax of the story. It wasn't something to be labeled, because Anderson would never admit it, but they were close already. Anderson's toxic mind forced it to pause, and of course, his death made Alucard believe nothing would come of it. Oh, how wrong he was.
Once Alucard finds out Anderson is a conscious being in Atom's body, he was ESTATIC. Over the moon. Fallen for Anderson all over again. The amount of passion Alucard has is an honest shock for Anderson and there is a lot of denial in there. Anderson doesn't want to admit any of it if he can help it. Alucard doesn't allow that.
Eventually, when Alucard can break into Atom and Anderson's dreamscape is when all hell breaks loose for them both. Alucard and Anderson can see each other physically for the first time in awhile and Alucard doesn't let go of that this time.
After the third meeting Alucard and Anderson end up admitting things to each other in their typical fashion. By here, they are 'dating' but Anderson will never admit it. Just who he is. Alucard doesn't really care that Anderson won't admit it. Alucard can see it on his face.
They have a lot of similar experiences and a very strong bond that everybody can see. Their romantic affection for each other is very deep, which satisfies that connection they don't have with Atom. Atom thinks their bond is cute.
Once they are more comfortable with each other, especially when Atom becomes a dhampir, the two actively conspire to pull Atom deeper into their mess. Alucard and Anderson end up using Atom as a way to challenge each other and get closer. Atom doesn't mind, but they will never admit it out loud.
There is a lot more little things but those are the basics! I wrote a lot WHOOPS. Also Atom has a website here for more info on them!
Enjoy!