They gained his confidence? Where was that said? My understanding was that they waltzed in and beheaded him, and the Sith have been sucking their dicks ever since.
If Ajunta didn't kill him in battle. And instead assassinated him. That says a lot of how powerful Hakagram Graush was.
But, I am 100% confident that Ajunta challenged him. It was stated in KotOR 2 during the arrival at his tomb.(when Kreia talks about him)
We know, that the Sith are adepts of kratoscracy. If Hakagram was purely assassinated instead of challenged in combat, I doubt the Dark Jedi Exiles would have been left to roam around if Ajunta did it cowardly.
__________________ RealistRacism: "Sheevites, much like the Banites, were meant to increase in power with each member. From Lightsnake to Gideon to Azronger, this was supposed to be the case. However, knowledge must've been lost in some kind of Gravid-like incident, as Az turned out to be a mid-tier debater with a sub-par track record, sh!itting all over Tempest's legacy. Sad."
The Sith, under their King Hakagram Graush, initially resisted the Dark Jedi's attempt to obtain their knowledge and subjugate them; however, Pall managed to recruit the King's Shadow Hand to their side, with the result that Graush was betrayed to the Dark Jedi, and Pall personally executed Graush with his own sword. wookieepedia. it states nothing about challenging him. it states that he was betrayed. i know it is not an official source, but it still helps.