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.