Why did Sarahi faked her death ?
I don't remember if I've ever written that down in a fic that I uploaded... Did you hear this plotline of mine among my many ramblings on YouTube?
And I'm so glad you asked this question, anon, and I'd be happy to answer. I hope you like very long answers! Here goes...
Faking her death wasn't wholly Sarahi's choice. Nor is it what she was going for.
Her intention was to just save Corey from Verucca, bring him back to Hogwarts from the Shrieking Shack, and just go AWOL for a week at most, as she ran with Jacob. But in the Shrieking Shack, Verucca cursed Sarahi, and she should have definitely died from that curse. To Verucca's knowledge, no one knew the counter-curse for the dark curse that was quickly killing Sarahi. But she didn't know that Rakepick DID know the counter-curse. Smug as hell and very proud of the fact that Rakepick would watch her favourite student die painfully, Verucca disapparated from the Shrieking Shack. Once she was gone, Rakepick perfomed the counter-curse on Sarahi, stopping the spread of the curse, and then took both Sarahi and Corey to the home of her girlfriend best friend, Adelaide Inkwell, who was a 'member' of R as well, but was secretly running a small group against R- a Rebellion, if you will.
Adelaide knew a very specific potion that would help cure Sarahi of her curse, and help deal with it's after effects. Sarahi's recovery would unfortunately be long and arduous, during which she would not have been able to defend herself or help her friends should R try to mess with them again. Eventually, once Sarahi was conscious, everyone reached the descision that it would be best for R to believe that she died in the Shrieking Shack, at least for a while. Not only would this give Sarahi the time to recover and regain her strength, it would also make it so R would no longer have a reason to target her friends. Corey agreed to this as well, and in an effort to make sure no one, including himself, had even a smidge of knowledge about where Sarahi was, elected to have his memory of the situation erased. Adelaide made sure that Corey reached near at least Hogsmeade safely, before she reluctantly erased his memory of her home and the fact that Sarahi survived. A now panicked Corey, whose last memory left was the image of a dying Sarahi, would go on to explain that Sarahi was dying when he last saw her, and that he doesn't remember how he got to Hogsmeade.
Basically, Rakepick and Adelaide, with Sarahi's permission, decided to let everyone believe that she was dead, for both her safety, and the safety of her friends. Sarahi would remain hidden in Adelaide's home/safehouse for two-and-a-half months, and the rest of the world truly believed she died.
Except Barnaby who believed that she wasn't, and after patiently waiting for Sarahi to return for two months, decided to say frick it, and went looking for her himself... Or at least he was by himself until Ismelda, Chiara, and Levi Kidd decided to invite themselves into the search party.