Kranox

Kranox, the Graven is a Hive Major Knight who appears in the Story Mission, The World's Grave. He wields a Boomer in combat. Kranox held the key to the World's Grave, before an unnamed Guardian slew him and took it.

Biography
Kranox is said to be an ancient Knight, who guards the World's Grave, acting as both its keeper and the Hive's "Keeper of Secrets."