If I could make it work, the idea is to have Anakin’s lines try and gently provide some of those answers. I want it to feel less like a scolding and more the fulfillment of something Ben’s been trying to get since TFA. Anakin’s still family, and it would still be a emotional moment for Ben, IMO, to see his grandfather after years of reaching out.
I was thinking the scene could go something like this:
Ben senses a presence and turns to it. Anakin’s ghost appears.
Ben: “Grandfather”
Anakin: “Ben.”
Ben: “Ben is dead.”
Anakin: “No. Kylo Ren is dead. Ben Solo lives. That’s why I’m here. (Gentle pause) Ben, she will need your help.”
“It’s too late. She’s gone.”
“It’s never too late Ben. You and Rey can bring balance to the Force. Finish what I started.”
Pregnant pause, Ben looks at Anakin.
“I know what I must do.”
Ben throws away Ren’s lightsaber, turns back and Anakin is gone.
As the camera pulls away for the wide shot, Anakin says:
“May the Force be with you.”
I like it. I would keep in Ben’s “I know what I have to do but I don’t know if I have the strength to do it.” and then have Anakin say “You do. We all do.”