Ancient Mayan Weapon

Source: (2013) The Road to Xibalba dungeon (Normal & Nightmare mode) during the Ever-Ending Days event.
Source: (2012) World drop from Mayan mobs during the End of Days event.
Skins: The Ancient Mayan Sword skin is also available as a Q6 Blue from crafting, the Council of Venice Envoy in the Blue Mountains, and the Weapons Quartermaster in Faction HQs.

Nameless Days Weapons

Source: (2013) Rumoured to be found in the Bounty of the Tlatlacatecoloh reward bag for killing vestiges. *confirm/deny?*
Source:
(2012) Q10 Blues from Morning Light Vendor, currently unavailable.
Skins: These are a silver recoloured version of the corrupted style of Mayan weapons found in the Darkness War dungeon. Note: the DW chaos focus is much larger than the Nameless Days focus.

Thank you Katelin, Shedevil and Kisshoten for the screenshots.