In my experience, I don't think that any one demigod is overpowered at the moment. I still think it's a little too early to talk about that, I think the discussion should more be on strartegy and on fixing bugs.
I've been called overpowered, cheap for killing players of a lower level, a chump for teleporting away when I almost died, and much more. I think it is just frustration a player is experiencing when they are facing someone more skilled than them, and Lord E has some good tricks in his bag if you are able to play him right, but then again, so does everyone.
A truth people must remember about this game is that if you play a good early game, it sets up for a great late game. The only time I ever feel overpowered is late game when I've almost like 50,000 gold total and have the all of the below items:
Plenor Battlecrown (+1575 Mana, +70% Mana Per Second)
Vlemish Facegaurd (+1050 Mana, +11 Mana Per Second, +4 Mana Per Second Aura)
Cloak of Flames (+1050 Mana+, 20 Mana Per Second, +30% Attack Speed)
Gives basically Unlimited Mana Pool at this point, achievable with any character
Mageslayer (+45 Weapon Damage, +25% Attack Speed, +12% Life Steal)
Orb of Vieled Storms (+25 Health Per Second,+25% Attack Speed)
Ashkandor (+12% Life Steal, +120 Weapon Damage, +25% Attack Speed, +15 Minion Damage, +15% Minion Attack Speed, 10% chance deal a critical strike for 4x damage.
So, at this point, combined with Vampiric Aura, I've got a ton of lifesteal, + damage, super fast attack speed, and basically unlimited mana, but it cost me like 50,000 gold to get it, so I outplayed you in the first place to get there. LOL last night I got up to 1,000 DPS and 184 HP lifesteal.
The thing you should realize is this build, minus vampiric aura, is achievable by anyone. I've tried it with other characters and had similar overpoweredness. People need to realize that items and strategy comes into this game, not just skills. What if one team is controlling all the flags? Or had better citadel upgrades, or better items? It's like you'd have to do 1v1 battles with no reinforcements, towers, or items to be able to call someone OP legitimately.