I think that is time for Victor Cassadine to return to PC. I know that he was supposedly killed in prison but , come on, he is a Cassadine.
Short explanation: Got out of the prison and allowed family to think he was dead to get away from the family. Started over as Tony Castle in Europe. He occassionally kept tabs on the family and only recently began to truly miss his real family connections. He returns to Port Charles as Tony Castle and is seen by various folks, setting up business deals. He hears Luke and hides. He sets up a meeting with Alexis who senses something familiar about him. After a few weeks Luke hears the name Tony Castle and freaks. He goes to Alexis. He asks what she knows about him and she says very little other than she is representing him in some business deals. She agrees to meet Tony again with Luke watching. Victor sees Luke before going into Alexis office and cancels. Later Victor has Alexis picked up by a car and taken to his hotel. He reveals he is really her uncle Victor Cassadine. He explains why he is back and asks her to set up a meeting with Luke as he doesn't want trouble from the Spencer family, he is a peaceful man. She agrees.
Then story can grow from there. But it would establish who he is quickly and his ties to various PC residents. Also quick viewers would recognize that Tony Castle was the name Victor's brother (Anthony Cassadine) used when he first came to PC years ago.
Just an idea.