Looking for manhwa about a murim guy who reincarnates into the modern world and enlists in the military. (please help!)

Hello everyone I really need some helping identifying this manhwa I read a long time ago and I completely forgot the name so let me describe everything I remember about it.

Its about a this straight laced guy who I think reincarnates into the modern world and enlists in the military if I remember correctly he wears glasses and he's a kind of "perfect guy" archetype, I remember there's a scene where a superior was going to try hazing him about his belongings and how he organizes them but they're so perfect he can't and I also remember another scene where he's doing a tear gas drill to endure tear gas in a room with no mask and the first time he does it gets to him just a little (he also makes a comment on the chemical weapons or smtn) but the second time he doesn't flinch or nothing, also he wears glasses (Don't quote me on this but I've done as much as digging as I can on google but I think he might be a Murim guy who came to the modern day/ maybe he came back?)

It's NOT these ones:

- The dark mage's return to enlistment

- steel eating player

I've described everything I can remember, hope someone knows cause I've tried my best tbh.