After she left, Ben couldn't sleep. He could sense her moving around the temple, consternation attending her, worry about some matter with the Resistance. Not his to worry about it. Sleep – with the mandatory loneliness and stillness and isolation with one's thoughts – had always been elusive for him. He'd start thinking about something from the day and roll it over and over in his mind, helplessly trapping himself in a loop. When he could grasp enough concentration and focus, meditation came more easily, and with that often came sleep, when, exhausted from such focus, his mind finally calmed down enough to let sleep come. Snoke had taught him from an early age how to clear his mind and fill his thoughts with the Force, to concentrate on his sadness and anger and hate and let that grow inside of him into strength. And from strength, from a place of protection and security, Ben had been able to grasp sleep more often.
Rey had pierced all of that, he knew. The more time he spent with her the more he felt the pull of the Light, and the more Light felt on his actions, the more difficult it became to sleep again. When he'd killed Han Solo, he'd felt not stronger, but weakened, and he hadn't even been able to bring himself to destroy the Resistance ship containing Leia. And when he'd given the order to have the last of the Resistance destroyed, he'd gone back on it and risked himself to save her – Rey.
He'd killed Snoke for her, too, hadn't he? To save her from his grasp, to beg her to be with him. He'd killed his master and would have killed Luke – no, none of that was for her, or for anyone else. His motives were selfish then, the desire for power and to kill his past and every memory of weakness.
He hated weakness.
Ben slid out of bed and put up a Force shield, sealing himself in his room in the medical wing of the temple. He knelt on the stone floor and closed his eyes.
Sentiment. Sentiment had destroyed the Empire, had led Darth Vader to his death. Vader, Ben's grandfather, had let sentiment come between himself and power, and he'd died for it.
Sentiment had been Vader's weakness. It would not be Ben's.
"Grandfather," he whispered. He was less sure if he'd be heard tonight. "Help me to learn from your mistakes. Help me to finish what you started."