That is correct. The time limit and stipulations on Diabound will likely remain for a while so other characters can get up to speed with their abilities. Other than the invisibility Echo, this is also going to be it for Bakura's major Echoes until that longer period you mentioned -- that is one thing we are going to insist on here, for the sake of fairness.

If the above is acceptable, you can go ahead and update your info post with the relevant information.