Each Manvantara is ruled by a specific Manu. Apart from the omnipotent supreme almighty-Vishnu & next in line to Brahma's place-Vayu; other deities such as Chaturmukh Brahma (present Brahma whose age is currently around 51 years) and Shiva, Shakti, Indra, 's cycle would have completed and they would have been united with the Omnipotent supreme entity - Brahman(Vishnu). Later on, Vayu ascends the throne of Brahma and the process of creation thus begins again after the mahapralaya(great destruction of the universe), Rishis and their sons are born anew in each new Manvantara according to the Vishnu Purana.