@HDR1 Thank you for your comment. However, I cannot make any promises that the mod will incorporate your suggestions, because:
1. I am unable to figure out why there is no journal update pop-up in-game after leaving the tomb.
2. I have tried giving Vash similar stats as other Jedi Masters, and combat difficulty and balance is not my forte.
3. There will be bugs if the mod actually shows Sion killing Vash on-screen, due to the fact that the mod has completely different cutscenes for Vash's death, depending on if Vash is killed by Sion or the player. The mod's intention is to set up Vash's character file (in UTC format) in the secret tomb that when she dies, the custom a_vash_ondeath script will be fired to trigger the cutscene of the player character leaving the tomb after killing Vash. If the mod shows Sion killing Vash on-screen, it will cause the PC to suddenly appear back in the tomb again, because the game will still fire the a_vash_ondeath script, which is meant for the scenario where Vash is killed by the player. Additionally, the journal will be updated to the same entry used for when the player kills Vash. There is no way to make Vash's character file consider these two completely different scenarios and cutscenes of her death. In short, there are technical reasons for why the mod does not show Sion killing Vash on-screen.