I mean yeah he has the memories of loving him so deeply the way Ren did, but he and Ren are different people and the one he loves is maki not the brother
Not any more he wont have the love of Maki’s brother in his memory, they re- set him in the last 2 chapter now he is only Arata and he remembers the time spent with maki after coming to his castle, they erased Ren memories that what I understood after reading the story.
So is he always going to have his exs memories ect in him like is he going to be like that everytime he sees his brother