Ghostfire

Ghostfire, also known as the Breath of Ugin, is an invisible colorless flame. It was used by Ugin against the Eldrazi. Along with the presence of three planeswalkers, it is the key to activating the Eye of Ugin.

The spell was recorded on the Dragon Scroll that Chandra Nalaar stole from the Sanctum of Stars on Kephalai. Ugin taught the secret of Ghostfire to the Jeskai Way of Tarkir. The Jeskai speaks of six fires that light the way to Enlightenment. These are the white soulfire, the red bloodfire, the blue mistfire, the black deathfire, and the green vitalfire. While vitalfire and deathfire are taboo for the Jeskai Way, mastering the other three opens the way to the sixth fire: the colorless ghostfire. Only a few people have ever learned to control ghostfire, and it is believed they are able to transcend natural elements and alter their fundamental nature and existence.

Jeskai Ghostfire Warriors had a shining mark like the rake of a twinned dragon claw, slashed across shoulder and chest. After the Khanfall, Shu Yun made a bargain with Ojutai that all the Ghostfire Warriors would die in exchange for the rest of the Jeskai people being allowed to live. However, Tae Jin was such a Ghostfire Warrior, who somehow had survived.