“SEND ME A PROMPT FOR A META” DOESN’T MEAN “RIP MY HEART INTO A MILLION PIECES” BUT ALRIGHT
I think Ben had a deep respect for Luke, and maybe even knew him as a child – I’d imagine Luke would visit his sister and his best friend pretty often before fucking off to the ass end of the galaxy. Considering that, I think Luke wouldn’t just be an uncle to Ben in name. He’d be a real part of the family, and Ben would’ve cared for him as such, as a mentor, a teacher, and a loved family member. As with all his relationships, Snoke slowly morphed that love into loathing, but that came significantly later.
As a cute little bab, Luke was probably Ben’s second favorite extended family member. Sorry, Luke. Ben likes the walking carpet more. But, yeah, he liked Luke a lot, and he especially liked hearing all the stories about the empire and the rebellion and pew pew!! x wings!! tie fighters!! and the death star goes BOOM!!! I mean, that is the shit to four year olds. And, because Ben is so closely tied with the Force, I’d imagine Luke taught him a few little things just to help him control it, even if Ben wasn’t immediately sent to learn with him. So even from a young age, Luke already had that mentor figure role in his life.
By the time Ben reached Luke, he was already more or less too far gone, too much in Snoke’s clutches. I don’t think there’s anything Luke could’ve done that would’ve stopped Ben from falling to the Dark Side, but the fact that Ben didn’t talk about jackshit certainly didn’t help. Not that he even knew to talk about it – Snoke’s conditioning and abusive behavior towards Ben began at an extremely young age, so that was normalized for him. He didn’t know there was anything wrong with it, so why would he bring it up? And even if he did know it was wrong, he was still conditioned to obey Snoke, and his apparent orders were to be a sleeper agent within the New Jedi Order, learning from Luke and simultaneously learning from Snoke. Maybe Luke sensed Ben’s reverberations with the Dark Side, but I guess he chalked it up to their bloodline and the influence of Vader. So, yeah. Not much that could’ve been done.
There was a time before he turned, though, and during that time, he still viewed Luke as a mentor. Snoke’s influence turned the imagine of the kindly teacher into the evil indoctrinator, so that. changed. in a very and sadly ironic sort of way. But that took time, too, and in his first initial years, he still looked at Luke as a role model. I think Ben was very soft-spoken and reserved by nature, and Snoke only served to isolate Ben further. At first, I think Ben would generally be rather well-liked in Luke’s class, known for being that quiet, smart kid that made funny jokes in the back sometimes. As the months passed, however, he withdrew more and more from other people, until he became something of a pariah, unable and unwilling to communicate with anyone and even lashing out at those that tried to reach out to him. I’m sure Luke saw and maybe tried to help, but Ben probably lashed out at him, too, especially as he fell more and more under Snoke’s spell. Ben still did well in class, he was still smart, but he was clearly going down a bad path. By the last few years with Luke, the evil seed that had been planted in Ben had grown thorns around him and had ensnared him too much for anyone else to do anything about it. I don’t know if Luke saw that, but if he did, I’m sure he would try to bring Ben back to the Light Side. After all, it was Luke that still saw the light in Vader. Luke would be the one to see it in Ben, too. But the problem is, Ben didn’t see it – or, rather, didn’t want to see it. And he couldn’t and can’t be helped until he acknowledges it.
I don’t know if Ben purposefully left Luke alive during the purge. I think that he certainly wanted to kill Luke, at least in theory. But there’s a huge difference between theory and practice. He was still just fifteen at the time, after all. He was able to kill his classmates, kill countless innocents so he could be reborn as Kylo Ren, but I don’t know if he could quite follow through. After all, he did still feel that pull to the light. And I think he recognized that if he killed Luke, it would be the point of no return. I think that scared him shitless, and he couldn’t do it.
Fifteen years later, though, and after he’s killed his own father, I doubt he’d be faced with the same dilemma if he saw Luke again. I think it would be a struggle, but he’d ultimately be capable of killing Luke. Much like after he killed Han, however, the act would certainly leave Kylo Ren more than shaken. He would finally be reborn in blood, finally and truly Kylo Ren – but I don’t think that’ll give him the solace he thinks it will.