Darkrai

Darkrai is the fierce Toa of Shadows

Matoran
Darkrai was originally an Av-Matoran to be recruited to battle Makuta forces in the Southern Continent. He was a great crafter and repairman. One dark day Makuta Vazahki came and ravaged Darkrai's home. He chased him into a Shadow Leech Hive and Darkrai hit his head hard enough to forget his name. Vazahki had already kwew it. He drained out his light, renamed him Darkrai and gave him a Toa Stone.

Toa
As newly formed Toa of Shadows, Darkrai only cooperated because he believed he was drawn to shadow without any chance of redemption. He underwent fierce training for Vazahki's Betrayal.

Southern Continent Elimination Training
Vazahki taught Darkrai the greatest extent of the art of Shadow, he also discovered that a small amount of lightning was intertwined with his element. Darkrai himself discovered the secrets of seperating intertwined elements, and thus acquired the elements of lightning and shadow. Darkrai learned the skills of melee combat by Vazahki's training robots. Darkrai became Vazahki's personal assassin and bodyguard in Brotherhood meetings.