In the anime, creatures called Daimons serve as monsters-of-the-day (in the English dub, they are varyingly called "Heart Snatchers", "Daimons", "Daimon Heart Snatchers", or "Demonaes"). These life forms are bred in special pods known as Daimon Eggs that release monsters from the most mundane of objects, and are employed by Kaolinite and the Witches 5. Appearing as red liquid humanoids, Daimons can possess a certain object to assume a unique form based on that object.
The first batch randomly possess objects and remain inactive until their target touches them. They have the ability to extract Pure Heart Crystals by using a black star tattoo hidden on their body. The tattoo emits a beam of black light which strikes the target right in the chest, and painfully removes the Heart Crystal from their bodies. The Daimons must continue to do so until the Crystal appears, or else the victim is left in a painful half-state.
The next two sets differ from the earlier Daimons as they have fixed-form by a Heart Snatcher Oven when created from that object by Professor Tomoe. This batch function as Eudial's bodyguards before the third batch is made to extract Pure Heart Crystals by kissing it out of their victims to find the ideal heart to awaken Mistress 9.
During the climatic battle against Mistress 9, every Daimon hatched and formed a barrier around Mugen Gakuen. After the battle ends, with the Death Busters no more, only one Daimon survived and bonded with the oven to become Rangy. Fueled by her desire to gather Hearts, Rangy attacks the city until the Senshi stop her.
When a Daimon is destroyed, it returns to the item that it was created from as the Daimon Egg ejects and breaks, releasing the spirit within. For most of Mimete's Daimons, the Heart Crystal returns to the victim afterwards.
In the manga, most Daimons are identical and are contained within Mugen Gakuen students who have pledged their souls to the Death Busters and can be released at Kaolinite's word. They are generally employed as an initial line of attack by the Death Busters upon confrontation by the Sailor Senshi. In the anime, there was only one case of their kind manifesting in human hosts. Most of the Death Busters are considered perfect Daimons due to the fact that they retained human appearances and have full control over the host's bodies.
The musicals also portray them as using human hosts, but have more in common in appearance with the anime version for failed versions.
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