The Prova Vandal can be purchased from Baro Ki'Teer in the Concourse section of the TennoRelay for 250,000 250,000 and 410410. Note that Baro Ki'Teer's stock changes with each appearance, and this weapon may not be available on a succeeding appearance.
The Prova Vandal was one of two melee weapon rewards for The Gradivus Dilemma, the other being the Machete Wraith. This would have been obtained by fighting 25 battles on any side during The Gradivus Dilemma and if the Corpus had won. As the Grineer won, players got the Machete Wraith instead.
Although it was never distributed in the game at the time, information about it existed in the Codex.
Prova Vandal is the first Vandal melee weapon to be released.
As with all Vandal weapons, only the energy color can be changed. Other colors may be selected, but will not show on the weapon, unless said weapon possesses a skin.