For Android users, make a new Google+ account. You'll use that account to link with the game data you want to sell. Once someone buys your offer, give them the data for that account. They will log it in their device, and restore the game data linked to it.
If you've linked it to your personal account, you'd have to go through the whole process of unlinking the data and account through the help center. When you're successful in unlinking the account and data, you can do the same steps as above.
For iOS users, make a new AppleID and link that to the Game Center. When a buyer pays for the account you're selling, give them the details for the AppleID. Once the buyer logs it in their device, they should be able to retrieve the game data after they input a name for the GC. To do that, they must run the app and choose the ‘Restore Data' (or similar) button somewhere in the settings.
Remember, if you're going to sell your account, it's better to link it to another email and not your personal one.
Link your game data to a throwaway account. That way, you can keep your data as you play. When you decide to sell your account, it'll be alright, since it isn't your personal email attached to it. It will also make the Castle Clash account transfer a much more convenient process.
If you're looking for a place to sell it, why not right here at PlayerAuctions? We have state-of-the-art security and the most trustworthy community. You won't find cheaper offers than the ones here as well!
Evolved heroes will increase the value of your account. To do so, you'll need the following:
Then you should go to the Heroes Altar and press the evolve button. Follow the instructions on the screen, and claim the blessed tome after the process. You can further evolve your heroes three more times. However, do note that requirements increase each time. The hero's levels also reset, so you have to level them up again as well.
Get the most profit from your account and evolve your heroes!