It’s just sort of vague how she is a more “perfect” creation than the Skywalkers. If anything, Anakin was more powerful and more susceptible to the dark side than Rey. I think Kylo can recognize where his family came from while actively choosing the dark. He doesn’t want to be like Vader, he’s actively looking to destroy the sith and start something new. He’s trying to be better. The imagery of Rey and Kylo destroying Vader’s mask supports this. Perhaps you could hint at this earlier in kylos visions. I’ve seen people talk about the fan film where Kylo kills Vader, and while I wouldn’t want to use the whole thing, maybe a few shots from that could reinforce this point.