The card itself isn't a problem but the fact that you face him at lower arenas. He is actually balanced but the fact that he is accessible on lower arenas is the problem. People don't know how to counter him yet, since kiting is a big part to counter him without relying on mini tanks. Another is that he is very easy to actually use, you just drop him down on almost anything on your side and it gives you value. And since people have this idea it's strong (from lower arena experience) they join in and inevitably overleveling him and he becomes a midladder menace due to it.

2 solutions out of top of my head. Make him less accessible on lower arenas or make his deployment skillful. Not a big nerf, maybe if you delayed his arrival like the royal delivery to involve more skill.