Entities with powerful brains are sometimes said to be omniscient, which includes knowing what others are thinking. Yamaraja has the power to know the mentalities of billions of living entities. “Before pursuing either course, however, they (the servants of Yamaraja) wanted to know about the Visnudutas from Yamaraja, who is also omniscient.”(Srimad Bhagavatam 6.3.10 purport)