twilight had recently gained her castle and met starlight but when she encounters chrysalis once again a dual accidental discharge of both their magic has resulted in both fusing together. now both have to learn how to get along if they have any hope of separating. but their new state has some complications. as both learn what really being a mother is about as a result of their combined biology.
now if only they knew how to separate things would have been just fine.
*cover art by NotTwilight aka mlpconjoinment*