Agnidev is god of fire. In early Hindu mythology, Agni is one of the most important of the Vedic gods. He is the god of fire, and much of his importance comes from the role of fire in sacrifices and rituals. As the fire which consumes the offerings to the gods, he is seen as the mediator between heaven and earth.
agni is considered as the most potent and visible form of energy;useful, and destructive at same time. so He is considered as supream God, who can just engulf anything into it and make it pure (let it nbe mind or body). No sacrifice is complete without His presence. So somehow the same agni will purify and clarify all the minds, with whatever vikalp they pass thru.