So it seems like the "right" way to finish Rasaad's Journey quest is to lose him permanently from your party, and have him take over and reform the new Twofold cult?
But what if I want to keep him in my party through BG2: Shadows of Amn as well as have him in ToB? What if I were playing a female character and wanted to romance him? Can you only romance him if you take the "keep him in the party" options and end up with him being outcast from both the old and new monkish orders?
Also... The Master of Combat dies FAR too easily in the conflict with the Shar cultists. This is poor design. At the very least, he should have a MINHP=1 "Imoen's Belt" type of item, but flee inside the temple when he hits 1HP (thus removing him from the combat when *he* is defeated, but allowing for the player to find him and talk to him afterwards if *you* win, by walking into the temple.)
Furthermore: The final conversation with him should NOT start automatically after the battle, but should be of the player's own volition - allowing time to save-and-reload in between the combat and the conversation, if you pick the wrong options by accident, and don't want to lose Rasaad from the party! Because otherwise your only option is to go all the way back to the auto-save that's before the big brawl... which means not only having to go through the fight again, but the interminable cutscene before it.
(And, as such, the final conversation should be able to happen either inside or outside the temple, depending on whether the Master of Combat was present through the entire battle, or forced to flee by hitting MINHP=1. Alternatively, the Master of Combat should head back inside the temple after the battle is over anyway, without talking, if he survived the battle. Rasaad, if alive, should then prompt the player to go and talk to the Master of Combat, and let the player choose to do so by going back into the Temple.)
And the cutscene before the battle is spectacularly bad, BECAUSE it is so long: it means that all the time you spend buffing is pointless because the talking goes on for long enough for half your buffs to expire!
Finally... When I wanted to keep Rasaad in the party, "Rasaad's Journey" quest disappeared ENTIRELY from my quest journal. As in, completely. It wasn't in the Chapter 2 part (where I started it), nor Chapter 3 (when I finished it), there was just a complete non-ending disappearance as if the quest had never existed as a quest or taken place, all that was left were some hanging journal entries that weren't attached to a quest of the name "Rasaad's Journey", completed or incomplete.
Why isn't there a third option, as there is with Keldorn ("leave Keldorn with his family for a day or two, then come back and collect him"), to go back, collect him and bring him back into your party after he's spent a few days putting the revised Order back together?
Because losing a party member at the end of a quest is a huge penalty for completing it: it means you've got to go find somebody else, who by now will be underpowered compared to the rest of the party, and probably have no gear. This is the worst design decision of all: one should never be penalised for doing the "proper" completion to a quest.