User blog comment:Supp0rt4n00bz/Broken Xin is broken!/@comment-6906412-20130729210937/@comment-6906412-20130801213835

15% armor reduction on 200 or 300 armor doesn't make much difference.... either way Randuin's/Frozen heart still exist and work wonders.

If you have anything less than that in the late game you're either a carry or an assassin, in which case you shouldn't have to worry about Xin since you are instakilling someone or your team should be peeling for you.

In short, if Xin builds glass cannon/carry, he can be bursted down easily. If he builds tank/bruiser, he doesn't put out nearly as much damage.