One of the rewards from the new Night Elf Heritage Questline is a new transmog, the Traditionalist's Kaldorei Blades. It is a new Night Elf Glaive-inspired mog that can be used to transmog one-handed swords.
There are three appearances, Glaive of the Blood Moon, Moonlight Glaive, and Duskrune Glaive, all three are learned when using Traditionalist's Kaldorei Blades, rewarded by completing the Night Elf heritage armor questline.
Note that those can only be transmogged by classes that can use one-handed swords and have a compatible weapon!
The appearances are not new, but were previously only available to Demon Hunters:
Unlike the Warglaives, which sheathe to your back, these glaives disappear when you sheathe them, only showing up in combat.