Usage of と in 「...その夢の完全なる成就とそれによる至福の喜びに浸っている」


In the second episode of Death Note, the main character reads a passage from a
school book:

> ついに夢を現実のものとした彼はその夢の完全なる成就 **と** それによる至福の喜びに浸っている

My question concerns the usage of と after 成就:

  1. Why not use に here? (And if it were used, would the meaning of the sentence change?)
  2. Is the passage being parsed as

(その夢の完全なる成就)と(それによる至福の喜び)に

where the function of と is to apply the trailing に to both

  * (その夢の完全なる成就)
  * (それによる至福の喜び) ?




> Why not use に here? (And if it were used, would the meaning of the sentence
> change?)

It would sound pretty weird, and arguably be ungrammatical. Your suggested
parsing of the sentence, `(その夢の完全なる成就)と(それによる至福の喜び)に`, is correct, although I
might have an extra set of parenthesis like `((x)と(y)）に`. I'm not sure why you
find this structure unusual though - it's the exact same thing we'd do in
English, like `he basked in X and Y`. We don't say `he basked in X in Y`,
which is kind of what attaching `に` to both nouns here would be like. The
function of `と` here is not really to apply the trailing `に` to both as much
as it is to join them into one big noun phrase to which the trailing `に` can
be attached, just like English.

If you really wanted to use `に` in both places, something like
`(その夢の完全なる成就)にも(それによる至福の喜び)にも` is grammatical but still sounds weird to me
because it strongly emphasizes that he is basking in both of these things,
which in this case doesn't seem to be relevant.

Note that there is a usage of `に` that can connect nouns with a meaning like
`and` (see #8 [here](https://jisho.org/search/%E3%81%AB%20%23particle)), but
it's mostly limited to emphasizing that there is something in addition to
something else and wouldn't really make sense here.




> Why not use に here? (And if it were used, would the meaning of the sentence
> change?)

It would sound pretty weird, and arguably be ungrammatical. Your suggested
parsing of the sentence, `(その夢の完全なる成就)と(それによる至福の喜び)に`, is correct, although I
might have an extra set of parenthesis like `((x)と(y)）に`. I'm not sure why you
find this structure unusual though - it's the exact same thing we'd do in
English, like `he basked in X and Y`. We don't say `he basked in X in Y`,
which is kind of what attaching `に` to both nouns here would be like. The
function of `と` here is not really to apply the trailing `に` to both as much
as it is to join them into one big noun phrase to which the trailing `に` can
be attached, just like English.

If you really wanted to use `に` in both places, something like
`(その夢の完全なる成就)にも(それによる至福の喜び)にも` is grammatical but still sounds weird to me
because it strongly emphasizes that he is basking in both of these things,
which in this case doesn't seem to be relevant.

Note that there is a usage of `に` that can connect nouns with a meaning like
`and` (see #8 [here](https://jisho.org/search/%E3%81%AB%20%23particle)), but
it's mostly limited to emphasizing that there is something in addition to
something else and wouldn't really make sense here.

