Vishnu, the preserver on the universe, devised a plan to make certain the Devas emerged victorious of their quest. In Devi bhagavatham its clearly described that "Sthri rupam of Lord vishnu is Parvathi/ durga". It is also described that lord shiva only has attraction to his shakthi Parvathi they https://www.youtube.com/watch?v=R8yE5JVNaHw