How to 'block' a specific epic from being used

[Steven Choiniere]

We have a multitude of Epics with similar naming (can't change due to naming convention). We have one specific Epic which we do not one of our team members using, even after selecting "Done" on the Epic, we are still able to choose the Epic link once creating new Tasks. 

Anyway to 'block' an Epic visually, still exists in the background but cannot be chosen then when creating new Issues?

Thanks!