Magnus could also manipulate Alec through emotional means. Since Alec might have certain feelings for Magnus, Magnus could play on those emotions. He could make Alec feel guilty or make Alec think that by doing what he asks, it would strengthen their relationship. For instance, Magnus could say things like 'If you really care about me, you'll do this for me' and Alec, being in love, might be more likely to comply.
One common way could be through using his magic in a subtle way. For example, he might use magic to create situations where Alec has no choice but to follow his lead. Maybe he makes it seem like the only option for Alec to protect his friends or family is to do what Magnus wants.
Another way is by using his knowledge and experience. Magnus has lived for a long time and has a vast amount of knowledge. He could use this to his advantage by making Alec believe that he knows best in certain situations. He could present himself as the only one who can solve a particular problem, and Alec, who might be a bit naive in comparison, would be easily manipulated into following Magnus' plans.
It's also possible that the real antagonist is Alec's own insecurities. Magnus might be using Alec's insecurities to manipulate him. So in a way, Alec's internal struggles could be seen as the antagonist. But again, from the title's perspective, Magnus is the one directly involved in the act of manipulation.
In the 'Alec gets manipulated by Magus' fanfic, Magus could use his charm to manipulate Alec. He might be very smooth - talking and convince Alec to do things that are not in Alec's best interest. Magus could also create situations where Alec feels indebted to him. For example, Magus could 'save' Alec from a made - up danger and then use that as leverage to get Alec to do his bidding. Additionally, Magus may manipulate the information Alec has access to. By controlling what Alec knows, he can control how Alec thinks and acts.
One characteristic is the focus on the relationship between Alec and Magnus. It could be their romantic relationship, like in many fanfics where their love story is explored in great detail. Another is the exploration of their individual personalities. For instance, Alec's loyalty and Magnus's magic are often highlighted.
One common theme is love and relationship development. It shows how Magnus and Alec's relationship grows and overcomes various obstacles. Another theme could be adventure, where they go on quests together while being in a relationship.
Jealousy can also be a common element. In these fanfics, there might be instances where Alec is jealous of Magnus's past relationships or his popularity in the Downworld. Magnus, on the other hand, could be jealous of Alec's closeness to his Shadowhunter friends or family. Another aspect is fear of abandonment. Given their different natures and the challenges they face in their relationship, both characters may fear that the other will leave at some point.
Alec is likely a character in the fanfic, perhaps someone who is vulnerable to manipulation. Magus is the one who does the manipulating. Without more context from the fanfic, it's hard to say more about their specific identities or backstories.
Another theme is the struggle against prejudice. Since they are from different 'worlds' in the story, they face a lot of judgment from others, and fanfictions often deal with how they overcome this. Also, the theme of self - discovery is quite common. Both characters grow and learn more about themselves through their relationship with each other.
Love is a very common theme. Their love story, how they overcame differences to be together. Another is the theme of acceptance, like Alec accepting Magnus' warlock nature and Magnus accepting Alec's Shadowhunter duties. And also the theme of family, as they both have different family backgrounds and how they merge their families in a way.
A frequent theme is also the power dynamics. Magnus has his powerful magic, and Alec has his position in the shadowhunter world. How they balance this in their relationship is often explored. Also, the theme of family acceptance is common. Alec's family and their reactions to his relationship with Magnus are often part of the stories.
Through the adoption, they might face external challenges like discrimination from certain parts of the Shadowhunter world. This would make them rely on each other more. They could have late - night talks about how to protect the child and in the process, they would share their fears and hopes for the future. This would strengthen their emotional connection and make their relationship more mature. Also, seeing each other as parents could add a new layer of respect and admiration for one another.