I'd say the Dragons caused the injury and the release of the King's Nen was the result. Hard to believe that he would have come to care so much for her, but I think that's the most logical thing--though Togashi hasn't exactly been following much logic as of late. I dunno. It didn't get us anywhere, but I liked it just the same. We finally get something resembling an idea of what Meruem's power is.