Summary
Chiyo is a mysterious, kind and cheerful girl who is actually a demonic lovecraftian entity that Yuu accidentally summoned in his uncle's basement. She grants Yuu the wish of becoming his elder sister. She has been revered as a goddess, demon, and even monster during her existence but only Yuu has mistaken her for an angel.
Powers and Stats
Dimensionality: 3D
Threat Level: God, likely higher
Powers and Abilities: Immortality (Types 1 & 9; Can live and has lived for an Eternity. Her physical form is just made for interacting with humans Her true form resides in a different dimension similar to Haru), Extrasensory Perceptions (Can see clearly even when Blindfolded), Aura (Has an Aura of Darkness), Shapeshifting (Can shapeshift into black goo), Fear Inducement (Glancing at her eyes caused Yuu to become aware of Death), Matter Manipulation (Created her clothes out of nowhere and even made them disappear. Her hair can change their shape and material property at will and can also create her clothes), Darkness Manipulation, Death Manipulation, & Time Manipulation (Stated that she could make someone endlessly relive their death while enveloped in an imperceptible darkness), Creation & Life Manipulation (Can create objects. Moreover, whatever she draws becomes real), Transformation (Can transform into human form or even other forms), Electricity Manipulation (Can create an Aura of electricity), Healing (Healed Yuu's wound), Fire Manipulation (Incinerated a Mosquito), Biological Manipulation (Was able to suck out the poison from different parts inside Yuu's body. Can suck out the heat from one's body. Can create tentacles from her body that can change into various forms and she can even control the biological functions of other beings), Black Magic (Capable of using Black Magic), Absorption (Can absorb living and non-living objects), Mind Manipulation & Body Control (Was able to command Yuu's thoughts and made him submit to her words. Staring at her can cause someone's mind to go numb and their body being under Chiyo's control), Plant Manipulation (Was able to mutate a Watermelon into a giant group of Watermelons. Was able to create an entire field of Four-Leaf Clover just by dropping a single drop of her darkness), Dimensional Travel (Her feelers or tentacles can catch anyone even if they escape through the Space-Time continuum), Water Manipulation (Can manipulate water for offensive and defensive purposes), Reality Warping (Her true form was stated to be capable of "Distorting" the World), Existence Erasure (Her Darkness can reduce beings into Chaos without any beginning or end), Status Effect Inducement (Her True form can induce a variety of status effect ailments), Poison Manipulation (Demon saliva has Aphrodiasical components to it), Duplication (Can create duplicates/splits of herself), Self-Sustenance (Types 1, 2, & 3), Large Size (Type 2), likely Resistances to Spatial Manipulation & Time Manipulation (Was hinted to be capable of existing fine outside of the Space-Time continuum due to her feelers being able to exist there)
Physical Strength: Unknown (Can cut through cutting boards easily but its unknown what the true extent of her powers are)
Attack Potency: Planet, likely higher via Hax (Her true form was stated to be capable of "Distorting" the World, stated she can make the sun ascend if Yuu ever wished such a thing)
Durability: Unknown
Speed: Unknown
Intelligence: Very High (Quite intelligent and knowledgeable)
Stamina: Unknown
Range: Interdimensional (Her Tentacles or Feelers can reach outside the Space-Time continuum)
Weakness: She is unable to revive the dead, saying its one of the things she cant do. Was unfamiliar with the modern lifestyle of the humans, though she is slowly getting more knowledge on it.