Hello hello! I'm absolutely canon blind to Sephiroth apart from Last Order movie which I watched like 15 years ago and naturally did not understand much (but the art was nice) - however, I'd really love if these two met! Kaworu has little concept of "you should stop because people are uncomfortable with your questions" so he will ask them a lot - hopefully Sephiroth is ready for that (or not, no one ever is :D )