Beast II

Beast II (ビーストⅡ) is a Beast-class Servant who appears in the Grand Orders of Fate/Grand Order.

Identity
Beast II's True Name is Tiamato, one of the few Primordial Deities in. Tiamat is an Earth Mother Goddess, a branch of 's forgotten goddess.

The gods were born from the union of the freshwater and the saltwater Tiamat. Then, the gods rebelled against their father, and seized authority over the world from him. Tiamat quietly approved of her children’s actions. It was proof that her love for her children outweighed her love for her husband. However, the gods then turned their blades on Tiamat. Tiamat wailed and raged, birthing eleven new Magical Beasts to oppose the gods.

At the end of the war, Tiamat and the Eleven Beasts were destroyed. The gods split Tiamat’s corpse in two, and used them to form the heavens and earth. It is said that this ritual created the world of humans.

Tiamat is the womb that was cast aside after the world was created. She is the Maternal Sea who was used as the soil to give birth to life, but once the Earth’s environment settled and ecosystems were established, Tiamat was deemed unnecessary and driven out into a World of Imaginary Numbers (虚数世界) -- described as the World of the Reverse (裏側の世界); it is unclear as to whether this term refers to the Reverse of the World (世界の裏側). This realm is not a parallel world; it is a space that contains no life.

Because the Earth’s ecosystems were established, Tiamat, who randomly designs life, was no longer needed. The goddess became nothing more than an obstacle to the process by which life forms acquired the intelligence determined by the planet. Since then, Tiamat has been waiting in the world of imaginary numbers for her chance to return to Earth.

Appearance
The black mud is also included in Tiamat’s height. However, the mud is made of imaginary numbers, so her weight is unquantifiable. Meanwhile, Tiamat’s volume is infinite. In other words, she is a four-dimensional pocket.

As of obtaining the Holy Grail that Goetia had stored within the heart of Kingu, the Sea of Life initially manifests a human-scale corpus known as Femme Fatale (ファム・ファタール), roughly 160 cm in height, clad with arm and leg restraints. Gilgamesh refers to this as Tiamat's Cerebral Corpus (頭脳体); it is believed to represent whatever remains of Tiamat's mind or consciousness. Upon partial awakening, the Cerebral Corpus becomes colored in red and black in a manner reminiscent of Dark Sakura.

Following the annihilation of the Cerebral Corpus, the Sea of Life manifests Tiamat in the form of a Titan. However, in the circumstance that Tiamat faces a mortal threat, she enacts Self-Modification to assume a draconic form.

Personality
It is impossible to confirm if Tiamat possesses anything resembling a personality. Perhaps she lost her intellect, or perhaps she never had one to begin with. Either is acceptable. The only meaning to her existence is to create, raise, and love her children. Thus, she set out to make war against humanity for declaring that it has no need for her. It is the functioning of an extremely primitive system: “If I do not exterminate modern humanity, I will be killed.” While she does hold a grudge and bears hatred and sadness for being abandoned after her purpose has been fulfilled, she is doing this to indulge in the "joy" of once again becoming the mother of everything.

Motivations, behavior towards master. One of seven billion. An obvious target to be obliterated. While the Second Beast is a repulsive invader to humanity, humans are terrifying aliens (extraterrestrials) to the Second Beast.

Babylonia: The Absolute Frontline in the War Against the Demonic Beasts
While Tiamat was returned to this world by the collapse of the Human Order Foundation and the power of theHoly Grail, she remained in a deep slumber. Setting aside the fact that Merlin's magic kept her asleep, once Tiamat was attacked by Chaldea, she woke from her sleep and set out to follow her instincts and purge humanity.

This did stem from Tiamat’s resentment, hatred, and sorrow for being abandoned as a used tool, but she was also joyously indulging in the repainting of Earth’s entire ecosystem and returning all of it to its mother.

It is due to this true nature that her class was chosen. “Goddess of Creation” and such are but false titles. She was deserted by humans, becoming the catastrophe most strongly rejected by human history. 

Other appearances
In Fate/Extra CCC, Tiamat was mentioned in BB's Potnia Theron skill. It is the authority of the Earth Mother Goddess whom BB compiled and absorbed from the abyss of the Moon Cell. It is the embodiment of the power of creation possessed by the mother goddesses and even branching to Tiamat.

Authority of the Beast
Authority of the Beast (獣の権能) is an Anti-Humanity (対人類) Class Skill that enhances the skillholder's capacity to harm Heroic Spirits, Divine Spirits, and all organisms birthed of the "Mother's Womb." This Skill is held not solely by the 2nd Beast, but shared amongst all the Demonic Beasts birthed of her womb.

Independent Manifestation
Independent Manifestation (単独顕現) is a Class Skill that lends the capacity to manifest independently within the temporal reality. Within seven days of manifestation, the Indian Ocean is smothered black; and Tiamat incessantly spawns Demonic Beasts to the end of devouring humanity. However, as the body of the 2nd Beast is the ocean itself, it cannot make landfall. Therefore, the role of annihilating humanity is delegated to her children.

At a Rank of B, this Skill is furthermore a declaration of the holder’s presence across all of space-time, and thereby grants immunity against existential threats by way of time paradox or the instantaneous imposition of death.

In the 7th Singularity of Fate/Grand Order, the 2nd Beast overcomes her restriction against landfall by use of Self-Modification -- altering her horns into wing-like appendages and taking flight. Upon the eradication of the Sea of Life within her immediate environs by the Divine Authority of Quetzalcoatl, she is able to spontaneously regenerate her domain by dispensing tides of Black Mud from the base of her feet.

Self-Modification
Self-Modification (自己改造) is a Skill that permits the 2nd Beast to remold her Saint Graph by use of the Black Mud of the Sea of Life. Growing from the scale of her standard Saint Graph (Femme Fatale), the 2nd Beast can assume the form of a Draconic creature of over 60 meters in length. In this form, the 2nd Beast obtains immunity against any attacks lower than a Rank of A++.

Sea of Life
The Sea of Life (生命の海) is a Personal Skill that expresses the Divine Authority of the 2nd Beast as "the ocean from which all life is born." Being that the Sea cycles the True Ether of the Genesis of Earth (地球創世記), the supply of Magical Energy available to the 2nd Beast is within the boundaries of the domain unlimited.

The substance of the Sea of Life is a Black Mud (黒い泥) that acts to pollute Saint Graphs (霊基), fundamentally remaking any organism that enters unto the Sea a "Child of Tiamat" that bears an arbitrary selection of the following skills: Self-Modification (自己改造), Environmental Modification (生態変化), Environmental Fusion (生態融合), and Unit Mitosis (個体増殖). Upon emergence from the Mud, the Children of Tiamat are imposed with a cellular-level Geis — a Enki-Keiyaku — automatically rendering them as enemies of Man. Servants are no exception to the process.

In the 7th Singularity of Fate/Grand Order, Kingu refers to the Sea as the Primordial Organism (原初の生命) and the Sea of Chaos (混沌の海) -- further stating that, amongst practitioners of Magecraft, the Black Mud is the substance referred to as the Mud of the Grail (聖杯の泥).

Nega-Genesis
Nega-Genesis (ネガ・ジェネシス) is a Skill of the same variety as the 6th Beast's Nega-Messiah (ネガ・メサイヤ). It is expressed in the manifestation of a generates a Conceptual Bounded Field (概念結界) that rejects the evolutionary course (進化) and the Genesis of the Earth (地球創世) expressed within the proper continuity of the History of Man (人類史), consequently proffering a resistance against the Noble Phantasms of any Servants generated as an output of the above processes.

Monstrous Strength
Monstrous Strength (怪力) is a Skill that permits the augmentation of its holder's Strength, borne of the holder's nature as a Demonic Beast. In the circumstance of the 2nd Beast, this Skill is expressed at its highest level. As of assuming Draconic form by way of reshaping the Black Mud of the Sea of Life, the 2nd Beast attains the Strength of a Titan.

Development
Kotetsu Yamanaka is the character designer for Tiamat.