Ok new rule when making any balance topics containing the words nerf or OP; think long and hard about how to play them and how to beat them, try really hard to prove yourself wrong before you even post anything.
Then, if you're still sure, include reasons why they're harder to counter than any other effective strategies. If you've thought extra hard, include some steps that might remedy it without making a worse problem.
I doubt the balance is perfect myself, so it may be that quite a few things need changing, but the onus is to prove there's a real need to change something, not fling your opinion out there and believe people will find that valid.
The balance is VERY good. They only gave Erebus a ~10% survival increase,10% move increase, 10% dmg increase, 250 life steal increase to bite and 1sec longer debuff duration, and 1sec longer stun and that made him go from the worst demigod in beta to the best.
But even when he was the worst, I did very well with him. I thought he was still pretty okay, and it's just that people tried to play him as a killer instead of the map control he's good at. You can mist on a flag and it makes it pretty annoying to try to cap taking 125dps except lvl 15+.
You could deny people killing you with mist, or his free warpstone called bats.
I've suggested some minor nerfs at http://forums.demigodthegame.com/348135 which I think will fix him.
People are being way too overzealous, not understanding the games balance, and thing something needs to be made half as good. When really, the balance is VERY good and it's more about how you play the Demigod, not what Demigod you play.