Why is な being used between two nouns?


I was watching a dorama and there was an introduction sentence with な between
two nouns, as if the first noun was actually a na-adjective.

> 「大学３年。彼氏なんてもちろんいない。思い切って私らしくない変身をしたハロウイン…。ハロウインの夜、残り物 **な** 私。」

That last sentence was actually written in the screen, so it's not even about
being able to distinguish の of な. Is that a typo or a different use of な?




残り物の私 is the standard way to say this. 残り物な私 is not a typo, but a nonstandard
yet somewhat humorous way of saying the same thing. I don't think there is a
name for this rhetorical technique where an ordinary noun is temporarily
employed as a na-adjective, but it's a tactic you'll occasionally see in
creative writing. Essentially, this is done to make a phrase sound informal,
interesting and/or humorous by using words in a slightly unconventional way.

Similar examples used in titles:

  * ボードゲームな夜  
(ボードゲームの夜 is more "standard", but it's uninteresting)

  * クレオパトラな女たち  
("Cleopatraic Women"(?) クレオパトラの女たち would mean something totally different)

  * シュガーな俺  
(This title is intentionally made to be puzzling, but those who read it would
notice some unique meaning is hidden)

Sometimes, employing a noun (or no-adjective) as a na-adjective can also evoke
some derived meaning. For example, see [ピンクの vs
ピンクな](https://japanese.stackexchange.com/q/55889/5010) and [無垢の vs
無垢な](https://japanese.stackexchange.com/a/55213/5010).




残り物の私 is the standard way to say this. 残り物な私 is not a typo, but a nonstandard
yet somewhat humorous way of saying the same thing. I don't think there is a
name for this rhetorical technique where an ordinary noun is temporarily
employed as a na-adjective, but it's a tactic you'll occasionally see in
creative writing. Essentially, this is done to make a phrase sound informal,
interesting and/or humorous by using words in a slightly unconventional way.

Similar examples used in titles:

  * ボードゲームな夜  
(ボードゲームの夜 is more "standard", but it's uninteresting)

  * クレオパトラな女たち  
("Cleopatraic Women"(?) クレオパトラの女たち would mean something totally different)

  * シュガーな俺  
(This title is intentionally made to be puzzling, but those who read it would
notice some unique meaning is hidden)

Sometimes, employing a noun (or no-adjective) as a na-adjective can also evoke
some derived meaning. For example, see [ピンクの vs
ピンクな](https://japanese.stackexchange.com/q/55889/5010) and [無垢の vs
無垢な](https://japanese.stackexchange.com/a/55213/5010).

