Considering Thanos and his army are all essentially digital characters, it is very easy to do a flashback and not worry about aging. I can see a reference back to that moment, if they wanted to do so. Especially since we never got to see it in Infinity War.

I think the first Nova movie should be about Richard Rider. The movie would end with him being killed by Thanos, and then the sequels are about Sam Alexander.

@AntIsBack sounds like too much build-up. Maybe a Disney+ series and episode one is about him

In my opinion, opening with the decimation of Xandar would be the only way to begin the film, should it happen...

I think that we could first be introduced to Richard Rider in Secret Invasion. After Thanos’ destroyed Xandar, Richard Rider, a member of the Nova Corps was the only one to survive. He could have disappeared by Thanos’ snap and after he came back, he could be searching for his brother, who could be working with Nick Fury and SWORD (in the comics Richard’s brother was working with Fury in Project Pegasus). Richard would find him working for Fury and could help the other heroes during the show.

Sam Alexander could be a normal teenager living on Earth. His father would have been a Nova Prime but he would have been killed when Thanos invaded Xandar. In Guardians of the Galaxy vol. 3, the Guardians would have to use the power of Nova Prime’s helmet to do something. As Sam’s father was dead, anyone would be able to use it. The team would discover about Sam, the son of the one who used the helmet before. He could probably be able to use it as his father. The Guardians could train Sam and Sam could help the heroes to defeat the main villain of the movie.

There is a Nova D+ show in dev. right now, I think given how phase 4 appears to focus on the fallout of the snap we'll probably see the invasion of Xandar.

^Source?

For one: I strongly prefer Richard Rider instead of that kid.

For Two: I really, really hope that they WILL show the destruction of Xandar and a potential Nova movie is the reason why it was not shown in Infinity War.