Swat doesn't work that way. You would be just in your house doing human things and BOOM "Swat GET ON THE GROUND"
USA would NEVER allow any nation to take a citizen like that, maybe a knock and talk but that's it.
Realistically speaking, things doesn't look too great for the MC...his weakest link (his aunt) is currently on the US and seems to be out of the MCs grasps....This is why I don't like being a pure swordsman...you don't have much utility skills in hand when it comes to such complicated situations xD not everything can be with brute force alone
Sh*t im pretty sure he knows that the people he's messing with can go after his loved ones, so he probably has a contingency plan for that, but if he doesn't have one and his aunt and friend get turned to hostages and he hasn't planned anything for that imma be pissed at his stupidity.
I hope that now that they're up to date they either fix some errors in the currently release chapters (the PR quality fell off) or start paying closer attention to future ones. The quality of the scanlation is really good minus the PR currently.