X defeated Muhammad of Ghori in the First Battle of Tarain in 1191 AD. Much against the plea of his wisemen, he pardoned Ghori, treated him with respect and let him go. In the very next year, Ghori came back with a bigger army and managed to defeated X this time. X was gravely ill-treated by Ghori and was blinded. Helped by his court poet and friend Chand Bardai, he is believed to have kill Mahmud ghori with his "shabdabhedi baan". His skill of hitting the target just on the basis of sound made by it come handy. And during the archery competition organized by Mahmud ghori, X displayed his skill. When Mahmood ghori praised him he heard his voice and attacked killed him. In order to escape death at the hands of enemies, he and his friend Chand Bardai stabbed each other. Identify X.