As days pass, Reimu's behavior becomes increasingly erratic. She starts to see and hear things that aren't there, and her actions become more and more out of character. Her friends and allies, including Marisa Kirisame and Sanae Kochiya, notice the change in her but are unable to reach out or bring her back to her senses.
: Community-run repositories for Touhou fan works. Reimu Gets Brainwashed -Final- -Kei kei kei loan-
Reimu's Mind Controlled Madness: The Kei Kei Kei Loan Debacle As days pass, Reimu's behavior becomes increasingly erratic
There is a large sub-community dedicated to "Dark Touhou" (Kuro-Touhou), where the whimsical nature of the series is traded for psychological horror or tragedy. Where to Find More : Community-run repositories for Touhou fan works
Their quest led them to an ancient, hidden temple deep in the forest, where they found the artifact and confronted Kei. In a final showdown, Remilia used her magical powers to sever the connection between Kei and Reimu, freeing her from the brainwashing.
Some problems aren’t worth solving.
: The most common repositories for translated versions of such doujinshi. Search for the artist "Kei" or the specific title. Danbooru / Gelbooru