Harbinger

Harbinger  is a Reaper who resides in dark space with the rest of the Reaper fleet. It is the overseer of the Collectors' operations, frequently possessing individual Collectors to fight battles personally. Harbinger's involvement first began two months after the Battle of the Citadel, when it made a deal with the Shadow Broker to gain possession of Commander Shepard's body following the destruction of the SSV Normandy. This did not succeed, however, and Shepard would go on to be resurrected by the Lazarus Project while Harbinger advanced its sinister plans for the galaxy.

Arrival
After Shepard activates the Project to delay the Reapers' arrival, Harbinger appears via a hologram to have a brief conversation with Shepard about the futility of the Commander's fight against the Reapers.