When Terrigen Mist is let into the world, the Inhumans come to find that there's a cocoon. They're as surprised as the Avengers, but also determined to claim the cocoon and the Inhuman inside. (They want to help the Nuhuman through their transition.)
In this continuity - I believe the new cartoon continuity - the Inhumans believe that all their descendants are in Attilan. I love the interaction between the two teams, despite the fact that there could have been more nuance in this story in general. (I wish companies, like Marvel, would accept that children's stories doesn't translate to dumbing things down.)
Still, seeing the royal family was nice, and the Nuhuman was a nice bonus: I was aware of him from other Marvel titles, and I think working him in as an ambassador for Attilan and the Inhumans who lives outside of Attilan - he wanted to stay with his home, family and friends - is a nice way to get the royal family involved again should Marvel choose to in the future.