Theories

A list of the major theories, their descriptions and evidence.

## Heart Race

The heart race theory is the idea that a fourth group of beings exists or has at some point existed. It is based on the fact that the three known races each have an associated playing card suit - diamonds for humans, spades for monsters, and clubs for winged - with no fourth race to be assigned hearts. On the cover of Rigmarole of Oshen, a broken heart symbol is shown, leading some to speculate that the hearts race is extinct (or simply believed to be). Kotori may be one or in some way involved with them as in this page, she has a faint heart on her chest, while Aria has a diamond.

This theory was later confirmed due to the advent of the Celestials, though this makes Kotori having a heart and not a spade even stranger.

## Human-Monster Transformation

The human-monster transformation theory is mainly centered around Five's past, and by extension, the previous four "units". It is believed that she may have once been a human child, as she was shown without a horn in a flashback. She was considered by doctors to be "a beacon of hope for the future". She also has unusually white skin.

A piece of paper in the background of page 756 shows columns marked 1-5. There may be a 6, as the end is obscured by the Human Princess standing in front of it. 5's column is the only one visible marked entirely with ticks; 1, 2, and 4 all have red X marks at the ends indicating failure, while 3 has a question mark.

This theory was eventually disproven when it was revealed that Five was a young monster being treated at the Lab for health problems related to her being unable to awaken an ability.

## Illusion Relativity

The theory of illusion relativity is the concept of illusions appearing differently to individuals, based on their memories. It was originally sparked by page 611, where Aria's horn was curved from Kotori's perspective, despite being seen as straight by Nino earlier in the comic. At that time, Nino had only seen a single monster - Five, whose horn also appears to be straight. In page 648, Solis is questioning Aria, who is using her ability's Facade to disguise as someone else to him. The girl she appears as is a teenaged monster who resides in Solis' home town, much to his bewilderment when he encounters the real girl later. Here Nino says that "the thing about illusions is that they're based on a person's memory". Aria states that her ability "tricks people into seeing what you want them to see". This theory was later confirmed.

## Timeloop Theory

The Timeloop Theory posits that Kotori is currently engaged in a series of timeloops surrounding the events of Oceanfalls, with each iteration becoming doomed in some way. It was first conceived based on an observation of how Kotori's theme, Firefly, repeatedly loops back, rewinds, and reiterates on itself throughout the song, as well as certain lines of dialogue such as "This is what you get for trying to stand up against destiny," and "Maybe this one is a dud again," seem to heavily support the idea that Kotori has repeated the timeline more than once before.

Other points of interest include Kotori's distinctive personality shift in the time before the story begins, with her choosing to distance herself from others and throwing herself into her work, which is a common trope among timeloop victims in media. Another, more recent one, are her uncanny "hunches" about the assassin that will t kill Prince Suvillan.

## Artificial Celestials

This theory posits that the lab was made to create artificial Celestials, and that the project was scrapped due to the Queen's disapproval. It was largely conceived based on Prof. Zachery's research proposal about the nature of Celestials.

## Experiment Three: Kotori

The Experiment Three: Kotori Theory posits that Kotori was experimented on at the Lab, and that she is Experiment 3. It is based on the fact that Experiment Three appears not to have ended in failure, and it is not known what became of them following the Lab's destruction. It also helps to explain Kotori's friendly demeanor towards Aria despite it being relatively obvious that the latter was human, her identifying with Cinders as being in a place where she could never truly belong, as well as how she seems to recognize Five. In addition, she has a 3 in her mark in the Fanart Booru, similar to Five.

Additionally, this can possibly work in conjunction to the Artificial Celestial Theory, as Kotori has a similar horn to the Queen's and a faint heart on her chest in one flashback.