From Halopedia, the Halo wiki
Whispered Truth is a mythic weapon in Halo 5: Guardians that can be called at Req level 5. This pistol is unique, as it fires in three-round bursts at the same rate of the Battle Rifle, while also increasing the user's movement speed when the weapon is equipped. The Whispered Truth can kill Spartans at a minimum with only two pulls of the trigger in War Games, as each individual round is just as powerful as a standard magnum round. It has a magazine size of 18 rounds with 72 more rounds in reserve.
Whispered Truth has the Latin phrase semper vigilans, meaning "always vigilant" in English, engraved on both sides of the frame. The phrase is otherwise known for being the motto of the Office of Naval Intelligence.
Halo 5: Guardians REQ cards
List of appearances