Why に used with ヨリを戻す and [person]ができる?


I have difficulty understanding the usage of に in two sentences I found from
manga.

> もう彼に彼女とヨリを戻す気は...
>
> He no longer wants to get back to his girlfriend.

and

> 私には素敵な彼女ができた。
>
> 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](https://japanese.stackexchange.com/questions/4440/%e3%81%8c-and-%e3%81%ab-
interchangeability-and-difference-in-meaning). 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?




First, understand the construct 彼に食べる気はない, 彼に帰る気はない etc. に is used to indicate
you are talking about his attributes (e.g. 彼に足はない、彼に知恵はない and so on).

So, when you want to say he doesn't have the attribute 彼女とヨリを戻す気 anymore,
you'd say 彼に彼女とヨリを戻す気はない

