I accept that the author pretty much gave up when the MC basically became The Hulk and started doing superhuman feats by simply swinging a sword around, but even then -- it caught me by surprise that the U.S's police was apprehending his aunt.
Sure, it's not every day that you have a literal superman waltzing around and destroying everything, but more than anything -- that sort of an extreme response is just overkill. It's just completely exaggerated and needless, it creates drama where there needs be none.
It'd make volumes more of sense for the aunt to be calmly interrogated, and perhaps illegally kidnapped by Korean mercs. But for the U.S police force to react that way against their own citizen? Come on.