How to make a Masterverse Revelation Castle Grayskull:

 Or how can Mattel make us Doubledip on a Playset.

Make the Playset the Hall of Wisdom.

That way Masterverse fans will have to buy it because it's "THEIR GRAYSKULL" and MOTUC fans will have to buy it because it's The Hall of Wisdom.

The playset would be Virtually the same Grayskull we've already have gotten: elevator, throne room trap weapon racks, computer. You've seen MOTUC Grayskull. You've seen Origins Grayskull, you've seen the Vintage Castle. You know what to expect. Just that this time we get a pretty castle with irredescent and metallic paintjobs with sparkly translucent parts.

I know what you're thinking. 

"so basically, you're suggesting having Grayskull styled innards on a new shell. How do we get castle Grayskull from this?"

Translucent turquiose overlays in the shape of Castle Grayskull's facade maybe with frosted back parts to better hide the Hall of Wisdom.

Then a few years later Mattel can rerelease the entire thing painted in solid MOTUC Grayskull teal...

If Mattel is smart, they make it the same proportions as MOTUC Grayskull with the raised ground ledge included  for a darker reason. By removing the Grayskull Facade elements in one of them you could combine BOTH playsets and make a Full 4 walled Grayskull.

I know it's both brilliant and dastardly... but it would still need a bit more, doesn't it?

Sparkly transformation He-Man figure.

We can also add the pyramid that opens up to reveal the most powerful ball in the universe.