Description
For years, Glimmermoon was the favored weapon of the Royal Executioner of Nemedia. The executioner himself was a Hyperborean, a gaunt, raw-boned fellow who brought the axe with him from his native land. The axe earned its name due to its glowing metal and half-moon shape. Nobody recalls the name of the executioner.
His executions were quite the show, his glowing axe whirling in a great arc to lop the head from the guilty. But he fell afoul of a plot to overthrow the throne, and his axe went missing in the ensuing turmoil.
This axe glimmers with an unearthly light, and blood seems to cling to the blade. It does additional damage.
Source
The Glimmermoon can be found in 
Legendary Chests.
Repair
This item can be repaired with a Legendary Weapon Repair Kit.