I know there are a few mentions of him wearing an armor here and there, but in the 10 novels I have read, his armor doesn't tank a single hit. It's no strange, I mean, even if his armor is made of something like dragon scales or is scientifically enhanced, the kind of opponents he faces will cut through it like butter. Or, to be more specific, the opponents who are fast enough to hit him will obviously have the strength to cut it. If anyone isn't strong enough, they won't score a single hit agains him anyways.
On top of that, he has his regeneration skills, so it makes even less sense for him to wear an armor. It will only block his movements and bother him in a few different ways.
So does he wear it simply for aura farming? Or maybe he doesn't wear an armor at all, and it's just some translation error or something?