The Swarm

The Swarm was a by-product of the Sacrifica process that birthed Cybertron's original population.

Over time, it became an all-enveloping black mass - a blind entity of destruction.

It consumed Jhiaxus and his Armada, before making to devour Cybertron.

Optimus Prime sacrificed himself to the Swarm in the hopes the light of the Matrix would purify it. His gamble paid off, and this long long child of Primus was given a new direction, becoming a creature of Creation rather than Destruction.

In time, the Swarm would evolve into the intelligence known as the Vok.

The Swarm's creation was not an accident. Primus created the entity with the plan that it would evolve to the point where it could combat and ultimately defeat Unicron in an event foretold in the Covenant of Primus as The Transcending.

For The Swarm to reach this end, Primus instructed the survivors of his original 13 to await in deep Space for The Swarm, and allow themselves to be consumed so as to guide the burgeoning entity in its path. But Unicron ordered The Fallen to kill the surviving members of the 13, and thus robbed The Swarm of these moral guiding lights.

Perhaps because of Unicron's influence on the Physical Realm, The Swarm imitated the often brutal nature of the Universe and became a force of destruction.