Why Is Immortal Sion Ready To Fight With The Exile In The Sith Academy On Korriban And Chase Them To

Why is immortal Sion ready to fight with the Exile in the Sith Academy on Korriban and chase them to the entrance, but not ready to step out the door and chase the Exile? And why does Kreia recommend going to the Academy first, knowing that Sion is there, and only after that coming into the cave? Can't Sion enter the cave for some reason? I can't get it... Does anybody know the answers?:)

Amnesiac Revan: The game must be dangerous, otherwise why play it?

Carth: Well... I do believe there is something seriously wrong with you!

Bastila *whispering quietly*: If only you knew...

On Korriban:

Darth Sion: ...You are her apprentice in name only. I am the Master, and that is why you will die!

The Exile: And it is time to find out who is better at mastering Force speed!

Lady Revan for @dairine-bonnet✨️

Well, if first it was supposed that Carth, according to the game writers and cut content, could redeem fem Revan, and after that they died hand in hand at the Star Forge, then here's my ending: Revan (probably, 'grey' Revan) convinces Malak to reject the Dark Side and they escape together on one of the Star Forge's ships before the station is completely destroyed. Nobody is even aware of it, redeemed Revan is considered a hero who died for the Republic/ or otherwise - maybe only a few people know the whole amnesiac Revan's story, and redeemed Bastila is declared the hero who 'defeated' Darth Malak...

P.S. The name of a possible short fic based on the story could be Presumed Dead.

Amnesiac Revan: What's the point in searching for peace if I don't even have the place I can call my home... You don't have such a place too, Bastila, do you?

Bastila: ...Dantooine is my home...