Iuchi Nagol

Iuchi Nagol was a shugenja of the Unicorn Clan who fell to the corruption, becoming a maho-tsukai.

Lore of the Burning Sands
In the Burning Sands Nagol was head of an order of shugenja that studied the desert's famed heartless wizards, the khadi. In his quest for power, Nagol researched the sorcerer's use of blood rituals.

Forest of Dreamers
Upon return to Rokugan Nagol expanded his quest to include Rokugan's own heartless wizard, Iuchiban, whom Nagol was certain drew his power as much from gaijin magic as from maho. The Iuchi and his followers moved to the secluded Forest of Dreamers, where they resumed their mysteries undisturbed. Less than a decade after their move into the forest nearly all of Nagol's cabal had been exposed to corruptive kansen.

Death
Three Iuchi Shugenja in his service realized that Nagol and the rest of their order had been tainted. The shugenja tricked their brethren and killed them one at a time. They came for Nagol lastly, knowing that he could not be tricked and would need to be confronted by all three directly in order to be overwhelmed.

Aftermath
The shugenja were successful and took proof of Nagol's treachery to the Iuchi Daimyo. The Iuchi leaders decided that the three shugenja would be demoted in status, but also given the Battue vassal name. They were familiar with the ways of dark magic and would be used as a weapon against corruption. The shugenja then returned to the Forest of the Dreamers and burned it down.