Well, I am at the end. I have saved the game just before talking to the Transcendent One and I have a serious problem or glitch ?
I talk the Transcendent One into merging with me again and when this is done, and the Nameless One walks to the middle of the roof and cast "Raise Dead" to resurrect his friends, the camera moves on its own (can't act on anything anymore) and move to the edge of the screen where it is all black and then...nothing. It stays like that indefinitely, and I am absolutely unable to regain control of anything on the screen.
I tried all the other endings and they all play fine. What's the bug ?

Well, I finally have been able to do the "raise friends" ending by loading a previous older save.

I remember having a similar issue once with another game (I think it was Baldur's Gate), restoring to an older save also solved the problem. I never did figure out what was causing this.