This is one of those weird ideas that come to me just as I'm falling asleep or waking up and gets stuck in my brain, so I HAVE to draw it.
Here's a mock doujinshi cover with my Lugiasona and Shadow Lugia.

If this were to actually be made, there'd be a detailed transformation sequence, and, well, at least some wholesome cuddling. 😉
Unfortunately this doujinshi will probably never come to fruition, I can't dedicate myself with my limited attention span to making an entire manga. 😅