This weapon was awarded from Operation: The Pacifism Defect event. The exact form in which the weapon can be acquired differs depending on the level of participation during the event:
All participating players in Clans that achieved the specified Clan Participation Score (e.g. 260 for Ghost clans) received an Ignis Wraith blueprint at the end of the event.
All players in a Clan that achieved the specified Victory Score during the event (e.g. 4,000 for Ghost clans) immediately received a complete Ignis Wraith with a free weapon slot and a pre-installed Orokin Catalyst.
Clans that place within the Top 10% scoring clans within their tier received the Ignis Wraith as a Research in the Chem Lab at the end of the event.
A fully built Ignis Wraith is now potentially sold by Baro Ki'Teer in the Concourse section of the Tenno Relay for 250,000 and 550. Note that Baro Ki'Teer's stock changes with each appearance, and this weapon may not be available on a succeeding appearance.
The blueprint from Operation: The Pacifism Defect can be traded, although the recipient must have a Mastery Rank of at least 9. However, the built version sold by Baro Ki'Teer is not tradeable. Note that the Nintendo Switch version of the game does not have access to the blueprint. SOURCE