I have difficulty understanding the usage of に in two sentences I found from manga.
He no longer wants to get back to his girlfriend.
I got a wonderful girlfriend.
In the first sentence, why 彼に is used instead of 彼が? Is it similar to に used in passive sentences?
In the second sentence, why XにYができる is used to mean "X took up Y" in the context of relationships? I don't understand why this particular construction used. I prefer XがYとできる.
I already read this answer. It doesn't help much because if I try to translate the two sentences above literally with "by/unto" it will make things strange and awkward. For example, the first sentence can be understood literally as
Getting back to his girlfriend by him...
It is difficult to translate.
What is the role of に in the two sentences above?