OK about all the explanations with the exception of QUOIST . The only one I did not get after about a week . I assume it is a Scottish Ringdove – did anyone find a dictionary with Quoist in it ???

Oh dear, I’m sorry for muddying the water even further – that was a silly mistake: I did mean to write ‘return of darkness-with-raptor’, as the clue says!

Reading the clue as:
AMEN (I agree) to (= added to) KRUM (the return of darkness) – leading to AMENEKRUM – with HAWK about (= around),
would lead to the letters of HAWK in the wrong order.

Reading it as:
AMEN to (KRUM with HAWK about), would either lead to AMEN KRUM KWAH or something like AMEN HA(KRUM)WK, depending on the meaning of ‘about’.

BTW, your (and Eileen’s possible possible) way of looking at it: ‘return of raptor-with-darkness [about]‘ is , in my opinion, very different from the opposite thing ‘return of darkness-with-raptor [about]‘(which is what the clue says).

Anyway, I don’t want to make a major point of this, certainly not within the greatness of most of the rest of the crossword.
But I just always want to fully understand a clue.

[The same thing happened to me (and to Rightback) in 2d where Araucaria changed the order of 'a.m.' and 'all' - which could, I say could, be justified in the end]

Eileen ~ #18 said:

“I wondered about thinking of it as ‘return of raptor-with-darkness [about] but I know that’s not very good. Wouldn’t it be good if Araucaria were one of those setters who drop by to help clear up this kind of problem?”

But if:

Raptor = Bird of prey = Hawk.
Darkness = Murk
Amen = “So be it” which I think is a valid way of hinting at “I agree” (although when I say it to myself I feel there’s a ‘hint’ of reluctance in said agreement!) then:

Return of Hawk with (including) Darkness = Kw….Krumah
About (around) Amen seems fine to me. Given this was the name (5,6) of a well known person born in 1909 then I would say this was an excellent clue and I doubt if Araucaria himself could add anything to clear it up.

Although I haven’t read or seen the play, I did think the quotation was better known than it appears to be [and it was in rightback's link].

Sil, I don’t think we’re going to get a satisfactory explanation of 25ac. I wondered about thinking of it as ‘return of raptor-with-darkness [about] but I know that’s not very good. Wouldn’t it be good if Araucaria were one of those setters who drop by to help clear up this kind of problem?

I’m with liz in feeling rather sorry that this Christmas special was published so early [I know that it's all to do with the way Christmas fell this year.] I tried to keep it but managed to resist only until the Saturday afternoon, which means that it’s a couple of weeks since I did it and it’s not easy to remember one’s thought processes. There have been a lot of puzzles in between!