Scorpius is the main character to be honest.
Scorpius meets and falls in love with Albus at one point.
He begins to feel jealousy toward Albus and Delphi, while refusing to let her tag along.
When Albus is forced to let him go, Scorpius has an emotional breakdown making him a mess.
He goes through lengths to get Albus back and puts up a fight.
Out of all characters, he meets Snape who points out what we’ve known all along which is that he has strong feelings toward Albus.
To fight off dementors, he has to think of Albus.
He is the one to go to Albus in the first place and they have their reunion.
At the end of the play, he realizes him and Albus aren’t actually friends. There is a new version of them. This took place during their hug.