Hello, all! This thread is basically me asking for advice that relates to the entire campaign, so if you don't want the game spoiled for you (or if you are in a game that just had a flashback for a halloween session involving a ship marooned in a desert), Please read no further!
So, I had a PC leave the group just after finishing In Search of Sanity and leaving the asylum - at the time it came just before game time, so I just had her wander off from the group - she was a psychic and kinda a weird duck so it wasn't necessarily out of character. But given how important the starting characters are to the story, I didn't want her to go completely to waste (and also all the writing of her backstory and how she's connected to both the party AND Hastur), so I've decided to bring her back in a somewhat different capacity - the Briarstone Witch herself.
The gist of her backstory that I put together is that along time ago she went to prevent Hastur's awakening, and succeeded (alongside one of the other PCs), but was shot into the future with no memory of that happening. Instead, she was corrupted by Hastur's influence and became the Briarstone Witch, being drawn to Lowls and taking a role as his right-hand woman and leader of the party before their memory loss.
When Ratch Mamby told the party about Hastur, his name called the King in Yellow's attention to Adriannah, whose mind-wiping had unintentionally removed Hastur's influence, and as of the PC leaving, called her back to the dreamlands to reclaim her memory ahead of the rest of the party. Currently we just hit the end of the second book, and are about to go into the downtime before they set out to sea in Dreams of the Yellow King.
Now she is in pursuit of Lowls, memory intact, and has become the Briarstone Witch once again. She will catch up with him at the Mysterium and essentially guide him on his journey to becoming a host for XD. She is going to lead the party on and get them to Carcosa to cultivate their XD corruption and merge them with Lowls at the end of the campaign.
So, with all that out of the way, I am asking for ways for her to be duplicitous to the party. My thoughts are that she sends them psychic and written messages attempting to "help" them follow Lowls, but also leads them into danger or helps to cultivate the corruption. I am not the best DM when it comes to being subtle, so I thought that you could help me form pieces of villainous advice that seems reasonable and like it's from an ally - but has those hints of darkness beneath the surface.
As well, what are ways to play up the Briarstone Witch in general, and the idea that she might still be out there in the world, or at least that she used to be? Any help you could give with me executing this twist would be greatly appreciated.
