First off, this entire game is illegal yet it's making millions, so chill. That being said, selling your account is neither dark nor illegal; I am unsure what this drama is about. If you can score a top-notch account for a few hundreds bucks and it seems worth it, do it.

If you want to "follow the rules", the only license clause that is questionable but also debatable is this: You may not use, copy, modify, sublicense, rent, sell, assign or transfer the license granted pursuant to this Agreement except as expressly provided in this Agreement.

But there are other portions of the license that explicitly indicate that account sharing or transfer is legal: User Information. Former Users. Users whose accounts have been terminated by any Graal Online administrator or LINUX Cyberjoueurs himself may not access the Graal Online system in any manner or for any reason without the express written permission of Cyberjoueur. Active Users may not knowingly allow former Users who have been terminated to use the active Users' accounts.