Magnus was reincarnated in a magic world. He led a simple life on Earth and that was something he liked rather than being dragged into conflicts or into adventures to save the world or something like that. He never cared to be the MC but hoped that he would have a pleasant life, much better than his previous life. Whether he could or not, read the tales to see. ---
The trap was set.
As planned, William made contact with Elisha and the conversation between them was good enough to get her communication number.
After returning to the academy, he kept in touch with her through this. This part was important because she had to fall in love with him. If not, he won't get her and his great-grandma might not get the revenge that she sought.
This was something he wouldn't let happen.
Though this plan was supposed to cause damage to the two families, for him the girl was more important. Even if the part to cause tensions between Frostwolf and Siren's family fails, he doesn't care. What he cared about was whether he could get Elisha or not.
He loves his great-grandma but this is not her life or era. It is his life and the final decisions have to be made upon what he desires, not what others desire.
So he put in the effort to not only impress Elisha but also her parents.
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