Embodiment of Scarlet Devil

The Scarlet Devil Mansion, which features in stage 3 and beyond, as well as on the extra stage, is a western mansion located at the bottom of yokai mountain on a causeway of Misty Lake. It is entirely scarlet in color, and the road that leads to it is also entirely scarlet. It has a clock tower, which rings only at 12 o'clock midnight. The head of this mansion is the final boss Remilia Scarlet, but since she is a child, the head maid and fifth stage boss Sakuya Izayoi is in charge of the place. The gatekeeper is the third stage boss Hong Meiling, who intercepts fairies who come from the lake. The extra boss Flandre Scarlet is also in here, as well as a great number of fairy maids who feature as regular stage enemies. Sakuya manipulates the space inside and makes it seem larger in appearance.

Playable characters:

• Reimu Hakurei — The miko of the Hakurei Shrine. Her two modes of attack in this game are homing amulets and needles.
• Marisa Kirisame — An ordinary magician. Her two modes of attack in the game are magic missiles and lasers.

Boss characters:

• Rumia (ルーミア, Rūmia) — Stage one mid-boss and main boss. She is a yōkai who has the physical appearance of a young girl. She has blond hair, red eyes, wears black clothing, and her hair is wrapped in a red ribbon.[1] This ribbon is an ofuda, and Rumia herself cannot touch it. Her ability is to create a sphere of night around her, but as it impedes her own vision significantly, it is not useful in combat. She usually spends her days fluttering around aimlessly.
• Daiyousei (大妖精, Daiyōsei) — Stage two mid-boss. An almost inconsequential character who received no character profile in the game; fans named her Daiyousei (lit. "Big/Great Fairy"). ZUN later attributed her as bright, playful, and full of expressions. Sometimes appears in dōjinshi with Cirno.[2]
• Cirno (チルノ, Chiruno) — Stage two boss, attacks with icicles. A leader of the fairies of the Lake of Fog, but is not very bright. Her hobby is freezing frogs and watching them revive as they thaw, but she tends to shatter them instead by accident. She radiates cold air year-round, and can stay awake even in spring and summer.
• Hong Meirin (紅 美鈴, Hon Meirin, alternate spelling Hong Meiling) — Stage three mid-boss and main boss, a Chinese-looking youkai acting as gate keeper of the Scarlet Devil Mansion. She is known to be a very humanoid yōkai who practices martial arts, but is generally friendly towards humans. She is often referred to as "Chūgoku" (meaning China) by Japanese fans.
• Koakuma (小悪魔) — Stage four mid-boss. Similar to Daiyousei, she received no character profile in the game and was named Koakuma (lit. "Little Devil") by fans. ZUN later described her to be like Daiyousei — whimsical, enjoys pranks, and doesn't think before doing. He also added that while devils are powerful as vampires and magicians, Koakuma is a rather weak one, therefore, she is a Koakuma (Little Devil).[2]
• Patchouli Knowledge (パチュリー・ノーレッジ, Pachurī Nōrejji) — Stage four boss and Extra Stage mid-boss. A scholar who is a friend of Remilia Scarlet, holing herself in the library of Remilia's mansion and becoming the de facto librarian. She has command over the seven elements (which the Japanese days of the week are named after, making her the "One-week Wizard") and is in theory an extremely powerful magician. However, her constitution is very poor and asthma often prevents her from reciting her spells. She has a tenuous relationship with Marisa, who tends to carry off her books without asking.
• Sakuya Izayoi (十六夜 咲夜, Izayoi Sakuya) — Stage five boss and stage six mid-boss. The head maid of the Scarlet Devil Mansion, armed with throwing knives and control over time. Sakuya is the only human living in the Scarlet Devil Mansion.[1][3] She was not born in Gensokyo, and the name "Sakuya Izayoi" was given to her by Remilia Scarlet.In Perfect Memento in Strict Sense, Akyuu guessed that she might have originally been a vampire hunter. Meanwhile, she is utterly devoted to her mistress.
• Remilia Scarlet (レミリア・スカーレット, Remiria Sukāretto) — Final boss, the mistress of the Scarlet Devil Mansion. A vampire who controls fate, but is weak against sun and rain. She claims to be descended from Vlad III Dracula although she is not. She is known as the Scarlet Devil as when she feeds, the blood of her victims stains her dress red. Apart from her unpleasant needs, she is hardly malicious enough to deserve such a title; merely childish, even though she is over five hundred years old. Although being a vampire is normally a lonely life, she has a good relationship with her many employees (including Sakuya and Meirin). Reimu is one of the few humans who tolerates her, and Remilia seems quite fond of her in turn. Marisa also gets along with her in exchange for access to her library. She prefers melee fighting to danmaku, but when she does resort to the latter, she is fond of red round bullets and knives.
• Flandre Scarlet (フランドール・スカーレット, Furandōru Sukāretto) — Extra Stage boss. Remilia's little sister, she has been shut in the basement for 495 years because of her destructive powers. Despite this, she likes her sister and doesn't usually try to escape. Most vampires hold back somewhat when fighting humans, as they plan to keep them alive and feed from them later, but Flandre was always fed prepared dishes and does not know her food comes from humans.

Other:

• Rin Satsuki (冴月 麟, Satsuki Rin) is a scrapped character associated with a portrait used to advertise Embodiment of Scarlet Devil at Comiket.