Heidar

Heidar was a Dominarian cryomaster who lived at the time of the Thaw. As the leader of the Cult of Rimewind, he styled himself as Master of Rimewind Keep, Chosen of the Blessed Cold and savior of the Boreal lands.

With his Rimewind magic he tried to undo the World Spell and plunge Dominaria into a new Ice Age.

Youth
As a child, Heidar was found out in the cold by his predecessor Gendrin. Gendrin recognized his inherent understanding of ice, frost, and chill winds, and also his natural talent and raw power. .

As Heidar grew in maturity and power, he was initiated in the Rimewind doctrine. First as an acolyte, and later as a task mage. When he and Lidra, the daughter of Gendrin, first experienced the encroaching warmth of the south he was terrified. He heard about the speaking of World Spell from the refugees who began to arrive. The refugees also told of the plagues that ravished the south with no cold to keep them in check. The warming world began to creatures as well. Behemoths went to sleep and never awoke. The glaciers revealed the rotten form of ancient beasts. The aesthir grew less common as well as the great owls of the north and the ice raptors that stalked the glaciers in his youth.

Arguing with Gendrin about the need to stop the Thaw, Heidar accidentally killed the old man. He didn't hesitate to take over his role as Master of Rimewind.

Alliance with Stromgald
Struck by fear of the Thaw, Heidar sent investigators out to scour the continent for anything that could help them fight back with force. He and his scouts discovered the Phyrexians buried in the ice of Ronom Glacier. Thanks to a temporary alliance with Haakon, the zombie leader of the Order of Stromgald, Heidar's scholars found the incantations needed to awaken the Phyrexians in the knowledge vaults of Lim-Dûl at Tresserhorn.

Alliance with Krov
It took Heidar yet another dark alliance to get the elementalism expertise for the job. He allied with Garza Zol, the powerful vampire queen of the plague-wracked city of Krov, to gain access to her Krovikan elementalists. In return Heidar helped Garza Zol crush the alliance between the Balduvians, the Kjeldorans and the Yavimayans in the southeast of Terisiare.

Revival of the Phyrexians
The Cult of Rimewind succeeded in their plans and reanimated many Phyrexian war-beasts with. When a Balduvian force under Lovisa Coldeyes stormed Rimewind, Heidar activated the Phyrexians, turning the battle into a massacre. The beasts went on a rampage across the frozen north, slaughtering everything in their path. Kjeldor retaliated, but the knights of Stromgald kept them in check.

The end of Heidar
Driven mad under the influence of Phyrexian magic, Heidar began attacking his enemies and allies indiscriminately even killing Lidra. Garza Zol, now aware of the danger posed by Heidar and his machines, ordered assassins planted in Rimewind to kill the mad wizard. Without Heidar's guidance, the Phyrexians ran amok and were easily destroyed by shamans from Yavimaya who arrived at Kjeldor's bidding. The forces of Kjeldor and Yavimaya proceeded to rout the leaderless Rimewind cultists and a Yavimayan ritual permanently ended Rimewind's unnatural winter and restored the Thaw to its proper course.