On March 17, 2015, it was announced that the Reaper Prime along with its related Warframe and primary weapon counterparts released during Update 8, would enter the Prime Vault and be retired from the reward tables on March 24, 2015. Any preexisting components or fully-built weapons will remain as is.
This weapon was available for a limited time from December 8 2015 through January 5 2016, either as part of the purchase-able Frost Prime Vault package or through drops in the Orokin Void.
Reaper Prime was again available from December 6 2016 to January 3 2017 as part of the Fire and Ice Prime Vault.
It is unknown if there will ever be an un-primed version of this weapon.
Removed from rewards on March 24, 2015, formerly unobtainable except through player trading of any remaining parts. Reintroduced on December 8, 2015 and available until January 5th, 2016 (Update 18.2).
Reaper Prime is the only primed scythe in the game.