Today's Crazy Theory is actually an old one combined with a new one.
The old theory is here: Is This White Diamond? (from 3 years ago).
The old theory was basically that the Gem that formed the pyramid temple in Serious Steven might be White Diamond.
My new theory, which I have written about in a couple of places, is that White Diamond on Homeworld is not the real White Diamond, but is instead some sort of puppet of White Pearl.
It has just occured to me that both could be true. The reason White Pearl has a fake White Diamond is that the real White Diamond somehow got turned into the pyramid temple, and White Pearl is covering that up for some reason.
I know this is far fetched, but I'm not named Ronaldo for nothing.