He deserved to absolutely whoop some insane ass before he went out.. I'm talking like that Jedi bunny slash cartoon from some years ago.
He should have lit up an entire level of a ship like Anakin did the trade federation dudes at the end of Sith, after the first order killed Leia.
Here ya go- FADE IN
Leia is killed on one of the rebel ships while Snoke and Ren look on. (It should be noted that Ren did choose the light in not killing his mother, in TLJ, and that that moment has been glossed over in this thread) Luke has received a distress call, but he arrives just after the fateful attack, and sees his twin sister floating frozen and damaged out in space.
Luke crashes his (once sunken in water) x-wing through a window on the side of Snokes ship. He begins a force rage merking up the entire level of the ship, powered by the anger over the death of his twin. Luke's power is amplified, and the force is strong as he deflects laser blasts, and uses the force relentlessly on the outmatched army.
Ren and snoke, seeing what Luke is doing, decide to go on the run in their own ship (for an organic laugh) and then, finally, Luke catches up. Luke, after sustaining some damage, kills snoke after an incredibly intense, but somewhat short, battle. Then it's Kylo Ren's turn.. But Rey has just entered the room. We have a scene similar to the turn scene for Anakin to Vadar in Palpatine's room, only in a larger, colder room. Rey is yelling for the fight to stop.
A short battle between luke and a disinterested Ren occurs, and Ren is bested. Ren Kneels, awaiting the death blow. He begins screaming for it- "Do it uncle Luke! Finish my training! Please!" Rey catches Luke's attention when she screams for him to be spared- "I need him to live!" Luke's eyes glow blue somewhere between Jedi and Sith at the end of his force rage across the ship. Rey is close, and appears ready to intervene and turn on Luke at the strike of a death blow. Ren looks at Rey, sensing her feelings, and seeing in her his potential new partner in lead of the order. A new beginning. Luke winds up..
A voice appears out of the fabric- VADAR, All three hear it- "Luke, your forgiveness saved me. Fear and anger took me to the dark side. Forgiveness in a moment such as this, and belief in the power of the light brought me back. Saved me. Luke, have hope, forgive again, and please don't kill my grandson."
Luke- "He could kill too many, he has too much anger father. It must stop now."
Rey, lightly sobbing- "No."
Ren- "lies! Darth Vadar never returned to the light!"
A new voice. Leia- "Don't kill my little boy, luke. Please."
Luke, after thought, has his eyes dim, and turns off his saber, steps away, and turns his back on Kylo, facing Rey. Looking her right in the eye. Kylo stands.
Looking at rey, speaking loud enough for Ren to hear, LUKE- "Your grandfather did turn to the light, Ben. Your entire family *Rey squints* resides with the light. The power you feel the need to live up to did not pass into the dark; your bloodline is not covered in darkness, and neither are you."
Ren- "I see that now. I can feel what the light did for an injured Vadar. Your forgiveness saved one of the most powerful Sith of all time. Brought him to the light... But your hate for me was so strong, that I, as a child, *saber extends*, needed to be murdered in my sleep!!"
Before the final words were spoken, the move to strike down Luke had begun. *slow motion sequence* Rey makes a move to stop the blow from striking Luke, extending her saber. Luke force grabs her, and force pushes her hard across the long room towards the door. Luke speaks his final words as the saber slashes through him- "Forgive us Ben, we are sorry." Luke disappears into the force.
The doors Rey was pushed into by Luke explode open, and some (hopefully mostly male, with male characteristics) resistance fighters come through guns blazing. The ship is now being bombarded heavily with fire; the room is shaking. Kylo repels rebel shots easily with his saber, and by using the force as in the beginning of TFA, returning some laser blasts in the direction from which they came. He backs into an exit, and right before the doors close, he sees the force spirits of every Jedi that has passed, from qui-gon, to Luke and Leia Skywalker, standing in the middle of the large room, facing him. Rey runs through the force spirits with her hand extended, unaware of them. She yells- "Ben!!" Talking to the entirety of those in front of him, REN- "I'm sorr.." The large doors close and lock. -FADE OUT
Luke should have actually got off that damn island for 10 minutes.