With that said, what does the novel say? Not paraphrasing, but exactly? The reason I ask, is for some odd reason, I found the dialogue between Han and Leia a bit ambiguous. Ealrier in the movie, Han only says that a young boy betrayed Luke. He doesnt specify by name. Perhaps he was emabarrassed because it was Ben, IDK. But the dialogue between Han and Leia sounds as if Leia is arguing that she wanted to send Ben to Luke, but then shows regret in her next sentence for sending him elsewhere, or away. If he did indeed go to train with Luke, how would Snoke had access to have seduced Ben?
Thats why Im asking specifically what the novel says. I dont think Ben ever trained with Luke. I think he was sent away somewhere else by Han and Leia and was seduced by Snoke. Im probably wrong and reading too much into it.