Is に forming an adverb in the following sentence? Or is it just a preposition?

Question

Context: a person is describing the punches of a boxer.

顔面ノーガードにスウェーから変則的な角度とリズムで放たれる拳。

Is に making an adverb of 顔面ノーガード? Or does it indicates that the boxer is throwing a punch to an opponent that is not protecting his face? My translation attempt:

After swaying without protecting his face, he throws punches with an unusual angle and rhythm.

In general, can に form adverbs when attached to a noun in this way? I know that it can do this with na-adjectives (as in 静かに), but I am not sure about nouns. Thank you for your help!

Answer 1

I am answering for sports tag. Semantically speaking, I think the sentence describes the boxer's style. I think 顔面ノーガードにスウェー implies not protecting his face and inviting the opponents punches. It's like a counter punch.変則的な角度とリズム describes the motions like the boxer Nasim Hamid does. When the punches came, the moment swaying back he throws the punch so that the opponents could not dodge. It is unusual/unexpected angle and rhythm to the boxer.

Edit:

I may think this “に” is listing particle like Naruto says in his answer. However, I think it can be adverb clause like the following: 顔面をノーガードにしながらスウェーで避けてパンチを出す。As not guarding his face and swaying back from the opponent’s punch, he is throwing his punch from unexpected and strange angle to the opponent.

I think he is always not guarding his face with his arms very well since he has a good athletic skill. So, he cam use his arms more flexibly.

Answer 2

A normal way to adverbially say "(while being) unguarded" is ノーガードで, not ノーガードに. ノーガードで戦う is okay, but ノーガードに戦う is highly questionable, if not entirely wrong.

This に can be interpreted in two ways:

1. に is a direction marker ("against; toward") and modifies 放たれる. 「顔面がノーガードのところに向けて放たれる拳」. The opponent is unguarded.
2. に is a listing particle described here and lists two nouns, 顔面ノーガード and スウェー, in parallel. 「顔面をノーガードにして、かつスウェーをしながら、放たれる拳」 The puncher is unguarded.

Unfortunately your "context" doesn't help much to distinguish. I feel 2 is more likely and natural, though. If 1 were intended, the sentence would usually be 「スウェーから変則的な角度とリズムでノーガードの顔面に放たれる拳」.