Garnet Dragon

The Garnet Dragon, also nicknamed by KR as "Ga-tan," is a Raid-level Boss whom he contracted. After breaking his original contract with her during the events of Kanami, Go! East!, he reforges one using his Overskill, Crimson Contract.

Personality
Ga-tan, despite her child-like appearance, is very old and speaks in an antiquated fashion. Despite her abusive behavior towards KR, which includes casually breaking his ribs to wake him up, she sticks around him even though she no longer has a contract with him.

She is rather passive about the events going on around her, holding little interest in the dilemmas and trappings of Plant Hwyaden.

Go! East! arc
After Kanami, Coppelia, and Elias Hackblade go on to challenge the Genius without Leonardo, KR uses  to bring himself from Yamato to China and participate in the battle. He summons the Garnet Dragon after motivating Leonardo to participate in the fight, and they ride on her back to go confront the Genius. Leonardo uses himself to knock Papus and Rasphuia off the Black Dragon, allowing KR and the Garnet Dragon to take on the Black Dragon alone.

Because contracting with the Garnet Dragon reduced her stats to a Minion-level monster's, KR destroys her contract by contracting with a thirteenth monster (over the twelve contract limit), reverting her to her Raid Boss status. He then re-contracts with her using  which allows her to retain her original stats, thus gaining equal ground with the Black Dragon. Although they manage to kill the Black Dragon, KR succumbs to the injuries sustained during the battle and resurrects in Minami, after which he joins Plant Hwyaden.

Around the time of The Sparrows Stretch Their Wings, KR informs Ga-tan that he told Kazuhiko about Kanami's impending return to Yamato after she forcibly awakens him by breaking his ribs. He reveals that he has no interest in Plant Hwyaden or the events going on in the server, and that he was only waiting for Kanami to come back.

Homesteading the Noosphere arc
Ga-tan is seen in her human form during the invasion of the Eternal Moths. Instead of helping in fending them off, both she and KR simply sit back and wait for Shiroe's raid to finish.

Trivia

 * Ga-tan calls Overskills the "Skill of the Giants," which suggests that such things may have occurred before, if a native of the Theldesian world has name for them.
 * KR's Overskill is named after Garnet, who is also known as the "Crimson Princess."
 * Ga-tan seems to be a reference to Alexstrasza the Life-binder from the popular MMORPG WoW.