Nana's Questions (2)

Is this familiar to any of y'alls ? It's quite vivid since it was in the middle of the story

The guy is pretty stoic, I think he was serving his military enlistment and some of the guys there were giving him a hard time but he was just finessing through it, one particular incident in when they were scheming with this Canon thingy but they accidentally let it go and guy catches it with one arm

So I had a list of my reads but my mom accidentally threw it out and I can't really recall most of it, if anyone knows the title of this plot, pls answer me ╥﹏╥

A girl was isekai'd in a murim style novel, she was the villainess and figured her step mum was trying to kill her, she also went away and stopped her engagement with the novel mc so now she's busy honing her murim. The last chapter I read was when she was taken away by the serpent or around the time she met a boy who lost his sister to the serpent.