In Curse of Strahd, during my current playthrough of it (with me as the DM) the NPC Kasimir is the party's ally ("Strahd's Enemy"). It says throughout the adventure (whenever Kasimir is mentioned at all) that he:
wants to travel to the Amber Temple, if the PCs are willing to help him do this, and track down the Dark Gift that will allow him to resurrect his dead sister, Patrina. In my playthrough, the PCs have agreed to help him and they are currently in Amber Temple helping him find this Dark Gift.
It says, on p. 90, in the description for Crypt 21:
Development. If she is restored to life by her brother (see "Kasimir's Dark Gift" in the "Special Events" section in chapter 13), Patrina (NE female dusk elf) returns as an archmage with no spells prepared. If the characters have her spellbook, she kindly asks them to give it back to her so that she can prepare her long-forgotten spells and help destroy Strahd (a lie). If the characters oblige, she repays their kindness by learning as much about them as possible before pursuing her own goals.
This implies that Kasimir would do this first before we face Strahd.
On p. 196, it describes a Special Event concerning Kasimir:
Kasimir's Dark Gift
If Kasimir Velikov [...] finds his way to area X42 and accepts the dark gift of Zhudun, he then asks the characters to accompany him to the catacombs of Castle Ravenloft so that he can restore the life of his centuries-dead sister, Patrina Velikovna [...]
If Kasimir succeeds in his quest, the newly resurrected Patrina (NE female dusk elf archmage) feigns repentance until she regains her strength and her spells, whereupon she travels to Castle Ravenloft and attempts to return to Strahd, seeking to become his vampire bride at last.
The first part implies he may want to do this before we face Strahd, but since both are related to Castle Ravenloft, it is ambiguous, so this part of the quote is perhaps not that helpful. The second part, though, implies again that Kasimir would do this before we face Strahd, since otherwise that part doesn't make any sense.
However, his entry in Appendix D says the following of relevance under Dreams of the Damned, pp. 232-233:
Patrina now speaks to her brother in dreams, telling him how years of guilt and regret have dispelled all evil thoughts from her mind and cleansed her tortured soul. But Kasimir remains unconvinced by her assertions, because he knows that Strahd has corrupted Patrina and led her down a path of evil and deceit. For that reason, Kasimir wants to see the vampire destroyed so that his sister can be rescued from her eternal damnation.
This implies that Kasimir would do this after we face Strahd.
So my question is:
Does Kasimir plan on resurrecting Patrina before or after we kill Strahd?
The first two quotes talks about the newly resurrected Patrina lying about offering her help against Strahd, then wanting to return to Strahd later, both of which only makes sense if she's resurrected before we take on Strahd. However, the last quote from Appendix D implies that Kasimir would want to kill Strahd before resurrecting his sister, in which case her lie doesn't make any sense.
Note that all of this is not taking into consideration that Strahd is supposed to "reform" after the end of the adventure; I don't believe that is relevant to my question, so let's assume that one of the PCs will supplant him as ruler of Barovia just to eliminate that possibility.