Cedric Nye said this quote

The final entity was the beast. The steel juggernaut that raked claws made of screams along the bones of their soul.All of the pain that Jango had endured as a child had never left his mind. That pain had created a sort of primordial ooze in his fractured mind that sloshed and bled until the beast was birthed from the suffering. The beast lived in a cage forged of willpower deep in the recesses of the mad matrix of his splintered mind. It rattled the cage and roared for release, but he was loath to ever set the beast loose…again.