First off. Been playing since launch. I really like this game. I've been waiting patiently for Stitch and finally, he's here hidden in a very short event behind a two character pay wall and unlock shards raised from ten to fifty.
In my opinion, you should have left him at ten. A "Marquee character" so to speak. The whales would have spent the money you desire to make him stronger and the rest of us wouldn't feel so disappointed.
I understand the need to be profitable in mobile games but I believe there are better ways to find balance amongst your player base.