<P> While the Vamana Purana describes Rudras as the sons of Kashyapa and Aditi, Maruts are described distinct from the Rudras as 49 sons of Diti, sister - wife of Aditi and attendants of Indra . </P> <P> Aswatthama, the son of Guru Drona is the avatar of one of the eleven Rudras and he is one of the seven Chiranjivi or the immortal ones . Drona did many years of severe penance to please Lord Siva in order to obtain a son who possesses the same valiance as of Lord Siva . Ashwatthama, the powerful son of Drona, though known as the part incarnate of Rudra, was really born of the four parts of Yama (death), Rudra (destruction), Kama (love) and Krodh (anger). Just before Mahabharata war, Bhishma himself declared that it will be virtually impossible for anyone to kill or defeat Ashwatthama in war as he is the part incarnate of Rudra . Bhishma said when Ashwatthama becomes angry then it will be impossible to fight him as he becomes a second Siva . No one can handle his wrath and fury . The tragic death of Drona made Aswathama extremely angry and these events led to the complete annihilation of Pandava lineage by the hands of Ashwatthama himself . </P>

Who are the 11 rudra avatars of lord shiva