|“||The decendants of Gaia are like children to me. If they offer their lives in order to empower a false life like me, should I not use that life to protect them?||”|
–(the Earth Dragon to Kotarou).
The Earth Dragon (地竜 chiryuu or āsu doragon) is an ancient familiar based on the Tyrannosaurus Rex, controlled by the Holy Disciples of Gaia.
The Earth Dragon has the appearance of a T-rex with hollow ghost-like eyes and no arms attached to it. It also has features similar to that of a shark; its upper-side is blue while its bottom-side is white.
Being an existing familiar of Gaia for thousands of years, the Earth Dragon had developed a sense of self awareness. He speaks in a deep voice and is actually very polite: he let Arata live after he interrupted his stroll through the forest, but not before slaughtering his entire team. He is also plays fair to a degree: he let Kotarou finish rewriting himself before they began fighting.
It is not known how old the Earth Dragon exactly is, but its been said that he's been revered by the disciples of Gaia for thousands of years.
The Earth Dragon is first seen fighting the hunters of Guardian; he kills them with ease then leaves. He appears again when breaking through the barrier that Kotori put up and tears her tree man-familiars to pieces. He then pursues the Key, but it is sniped and killed by Shizuru, so he turns around and leaves.
The Earth Dragon had just finished killing Kotori's familiar, Chibimoth, and spots Kotarou. As Kotarou attempts to flee, the Earth Dragon attacks him, putting him in a near-death state.
When a hunter is about to attack Akane in the forest, the Earth Dragon skewers him with its tail and fights the other members only to emerge victorious. In the final phases of the route he is summoned by the disciples at the command of Akane to fight Kotarou. Kotarou has to continuously rewrite his aurora in order to make it able to harm the dragon, he pierces the dragon with an extended blade aimed to destroy the Key. Though the dragon is still able to fight, he disappears due to the disciples running out of their life-force which fuels his power.
The Holy Disciples revived the Earth Dragon. Akane, possessed by the memories of the Holy Women, let Midou take control of it, with the condition of keeping the Key from getting killed.
He used it, along with Fuego, to attack the Occult Club members who have gathered in Kotori's Workshop. Concluding that Midou's lifespan will eventually run out due to the level of the familiars he was controlling, Kotori decided for the members to escape. To add, she brought her parents, whom she turned into familiars after their deaths, to stall the dragon, but they were defeated. However, members of the Bayern Knights arrived and discovered the Key. As they proceeded to attack it, Midou was forced to protect the club members. He soon died as he was completely drained of his lifespan and Fuego engulfed him and the dragon in flames.
It is the route in which the dragon actually speaks. He is first seen in the forest fighting Mikuni where he kills Mikuni with his own boomerang, then leaves. A few years later he slaughters Imamiya's team because they disturbed his walk through the forest, he decides to be merciful and spares Imamiya's life.
As Kotarou enters the tunnels of Gaia, he appears through a large magical circle and challenges Kotarou. Though the idea of only one hunter challenging him doesn't peak his interest, he knows that Kotarou is different from all else and claims that their meeting is fate. He lets Kotarou finish rewriting himself before they fight, as a result he loses.
The Earth Dragon has no extreme weapons but it is the strongest familiar possessed by Gaia.
- Strength, Speed, and Stealth: The Earth Dragon's strength is only matched by its colossal size; it can tear through trees with ease, its tail can pierce and shatter his enemies with a single swipe. For its size it can move very quickly and quietly through crowded areas with little shaking of the ground.
- Durability: The dragon's skin is incredibly durable, Kotarou had to rewrite his blades hundreds of times in order to make them able to harm him.
- Intelligence: As mentioned by Kotarou in the Terra Route, some ancient familiars posses minds of their own. The Earth Dragon has the ability to speak, he is a skilled fighter, and somewhat of a tactician, as he makes use of his enemies own weapons.