I LOVE this champion. I think it's one of the best champions you've ever created (and that's saying a lot). I love how he transforms, his boulder is awesome, comboing E with transforming and then ulting the enemy team feels awesome and his weaknesses and strengths are easy to guess. He is an awesome concept overall.
Now even though I love his boomerang, I wonder why it has so many strange mechanics to reduce the damage. I feel like it would be better to nerf it's damage and make the damage not fall off when you hit something and making it hit twice than having those strange mechanics that make you feel bad when you hit minions.
The rest of his abilities are awesome and shouldn't be touched apart from balance changes. GJ with Gnar, keep giving us awesome champions!
EDIT: Please remove this thread, It got duplicated.