Bottom line, it's time to make some adjustments to how this is obtained. I have traded in 800+ Gugrusaurus' and 600+ Lik in a 6 year period and I have yet to get either item. I've quit twice due to the frustration and after 300+ more fish since I have once again registered for punishment, I'm getting to that point again and it's only been a week. Yes I know people have traded in more fish without an item but I truly don't care because I've had enough. It has been stated that there will be changes to how mythic weapons and items are obtained and I hope that the Ebisu will be included in these changes.
While we are at it, you should add some more ways to obtain the Heron and Seagull rings.