Like other Cogitors, Eklo was a human philosopher who about 2000 years before the start of the Butlerian Jihad, abandoned his physical body and the material temptations that went with it and had his brain transplanted into a preservation canister. However, unlike some of his companions he remained on Earth.
Eklo played a key role in the rise of the Titans, and indirectly in the rise of the thinking machines. He was visited even by Erasmus. His role in this chain of events left him wracked with regret.
His Secondary, Aquim was a former mob leader against the machines, however by obscure means and reasons, Eklo took care of his rescue and rehabilitation, and Aquim served him ever since.
The Cogitor tried to balance his earlier mistake about 1,000 years later. Aquim brought him to Iblis Ginjo and started to counsel him to instigate a slave revolt against Omnius.
Eklo was killed for his actions by the Titan Juno during the revolt, shortly before Earth was decimated with atomics.