ToME: the Tales of Maj'Eyal

I got the new Zigur unlock, allowing new characters to betray an escort before they take the Zigurath trial. Then, with a dwarf mindslayer, I betrayed an escort to get the mindstar mastery tree, but that didn't ban my magic equipment or runes. Furthermore, with later escorts (still pre-Zigur), I could not betray them, but I could learn magical trees and abilities. I don't know if this is intended or not, but if not could lead to some rather overpowered builds.

If I understand both you and the game, it's intended for players to be able to betray an escort and yet later learn magic-- possibly even betray Zigur.

The only wierd thing is that you were unable to betray further escorts, but you're not supposed to be able to betray once you have any spells or runes. With later escorts whom you couldn't betray, did you at that point in the game have any spells or runes?