@eddiekart
The rest of the manga can be written off as whimsical thinking. A sniper rifle can kill someone like that, the joke is that a novice with no training who was reluctant did it. Being able to erase your presence in martial arts is a cultural idea, the joke is that she is able to do it thanks to social anxiety. The fact she even has an assination job is believable because this positions do exist, the joke is she found it on accident. The silencer joke doesn't make sense because that shows the author fundamentally doesn't understand how a silencer works, like most people. A silencer wouldn't help or hurt in that situation. He went to the extra effort to draw something, putting more work on himself, for something the doesn't work. If anything, the joke would have been funnier if this was her first time using it and she realized it doesn't work like it does in the movies. I would have found that hilarious. The joke in that scene is she's going to kill someone in a train, that's funny. The ignorance comes in by implying she would be able to use a gun.
It also gets contradicted later because the news report speculates "it could be a result of a
slasher" implying she used a knife. Even the artist admits firing a gun in a loaded train is retarded himself by his own writing.
Would you accept it if next chapter the artists says she has the ability to tear dimensions in space to kill everyone in a mile radius because "lol you just have to accept everything the artist does, it's all silly xD"?