It's a pretty simple principle, DC, that even 5 year-olds are able to master: if you don't eat your vegetables, you don't get any dessert.
So, in other words--if you're not willing to do the work of restoring the Marvel Family...
...you don't get to use their villains for someone else's storyline.
If you want to use Mr. Mind, DC, you've got to resolve Billy and Mary's banishment by the Wizard, and Freddy's situation, etc. It can't be that hard, can it?
But until you do that, you really don't get to enjoy the fruits of their villains and supporting casts.
So get on it, DC, or it's off to bed with no dessert for you!