So after seeing some witcher!Yennefer fanart, going to ao3 to look for fics and finding these [x] [x] I'm craving more
Since Sapkowski said adult women can become witchers that's when Yenn gets turned in her adult years. At what age? You decide. To be cliche she's turned by the Cats. Either to save her life or to test a new set of mutagens that creates new witchers or both, again you decide.
Instead of Geralt going to Temeria it's Yennefer and here she finally crosses paths with Triss after so many years. Triss is shocked to feel how little her magic has diminished since her Trials. Yenn's witcher signs are the strongest she's ever seen and once the contract is done and Yenn is tended to Triss kinda jumps her bones. I mean can you blame her? She saved the princess instead of killing her like some many others would've and on top of that she nearly lost Yenn after having just gotten her back. So yeah Triss is feeling rather strongly.
Unfortunately their romance ends as quickly as it starts because the Brotherhood (of Evil, Teen Titans reference lol) shows up after Triss contacts them kinda snitching on what's happened to Yenn but she thinks she's helping. She's not. And Yenn quickly makes her escape.
At some point Yenn meets a bard named Essi/Priscilla and this bard is absolutely enamored by her. Essi/Priscilla has heard so much about witchers from her fellow bard and somewhat-brother, Jaskier, who sings the tales of the White Wolf of Rivia. Yenn tries to escape the bard on Unicorn, her grey mare, but bards have some kind of magic of their own because she just teleports wherever Yennefer is. Eventually Yenn just gives up and lets Essi/Priscilla travel with her. Soon enough Yenn becomes known as the Black Cat of Vengerberg (because yeah we're going with the color and animal theme for her too. Thanks for letting us rip you off Geralt appreciate it.) The sorceress turned witcher and her own adventures are being sang around the Continent as well.
* Yenn does eventually meet Geralt when Essi/Priscilla and her stumble upon him and Jaskier in Rinde at the shore of a lake looking for a djinn. Geralt is trying to find the djinn so he can get some sleep and Yenn calls him an idiot before knocking him out with a powerful Axii. Jaskier laughs, thanks her and invites the two to stay a bit and picnic with him while they wait for Geralt to wake up. Yenn honestly thinks about going after the djinn herself only to be stopped by Essi/Priscilla. The two women leave but not before Yenn tells Jaskier he's got a curse hanging around him, she'd help if she could still do that type of magic so instead she tells him to go see the sorceress Triss Merigold.
This part is if you choose to ship her with Essi:
The next time the four meet it's the coast and there's sirens. Yenn gifts Essi a blue pearl and finally falls into bed with her. All seems fine until Essi catches the pox and is on her deathbed. Yenn goes looking for Triss and begs her to heal the bard. When Essi is cured and well on her way to recovery Yenn, revealed and overjoyed, sleeps with Triss. Then continues on with her adventures with Essi.
This part is if you choose to ship her with Priscilla:
While stopping in Novigard Priscilla is attacked and poisoned but manges to escape and find Yennefer. In desperation Yenn seeks out Triss to heal her bard. As Priscilla is healing and recovering Yenn, revealed and overjoyed, sleeps with Triss. Then continues on with her adventures with Priscilla.
The dragon mountain comes and Essi/Priscilla is happy to see Geralt again but why isn't Jaskier with him? She tries asking but gets nothing. Essi/Priscilla instantly understands, they had a fight. She travels up the mountain with her witcher and Jaskier's. He sends the two jealous glares. And when all is said and done, when egg and golden one are both safe that's when hell breaks loose. Borch tells Geralt he can't run from his child of destiny forever. Yenn slaps him because how fucking dare he. She'd give anything for a child of her own and here Geralt is wasting it all. Geralt turns back on her and yells at her about leading Essi/Priscilla and Triss on. "You can't have both, Yenn!" Before he storms down the mountain leaving Essi/Priscilla standing there in tears. Jaskier is going to kill him but it's for the best she knows now rather than another decade later.
Yenn tries to salvage what little she can but the damage is done. Essi/Priscilla wants nothing to do with her. "I thought...you and I..."
Yenn doesn't see her bard for a while after that and heads to Sodden.
At Kaer Morhen, Triss slaps Geralt telling him he had no right to meddle in her affairs. But hugs him and sobs soon after.
* it felt weird to try and have them sleep together when nothing really would've ever happened if it wasn't for Jaskier
Let me know if you guys want more! 😁