I'm playing it a lot in my arena farming deck, and I feel it's strong enough as it is. Saved me a lot of times.
Creatures produced are agressive, frequently have PC and CC capacities and nearly no downside (you can have a 0 HP creature, very rare).
It's a perfect recycler for allies you're finding not strong enough in a given situation. Big dragons with dive, voodoo doll with steal, etc.
The only thing that balances him is his low health right now.