Cerberus Nova

Formed after the Reaper War in 2187 CE by a man known as Lamar Tarleton, Cerberus Nova is a human survivalist group composed of fragments of the old Cerberus and components of the Terra Firma Party in addition to several old shadow broker contacts, mercenaries and Alliance agents.

Formation
During the Reaper War, the Illusive Man turned to indoctrination to ensure the loyaly of his men. A group of high ranking Cerberus Operatives which Tarelton was a part of, caught wind of this and immeaditley defected; swearing that after the War, they would restore Cerberus and form it into what it should have become.

However, they never anticipated the destruction of the Mass Relays and thus they knew another galactic conflict was an inevitabilty. Being the only member of the Cerberus defectors with a military background, Lamar Tarleton was made the leader of Cerberus Nova and established their base on Soyuz, a colony in the Gliese 581 system.

Military Strength
When Tarleton defected, he took 3 battalions worth of men with him and his fellow defectors managed to steal some of the Illusive Man's finest engineers, scientists and ships making Cerberus Nova a force to be reckoned with.