On the 16th day of the war, Karna was appointed to protect Dushyasana from the clutches of Bhima. Soon Karna picked up a sword and rushed on to Bhima. Soon they engaged in a sword fight, when Bhima was about to stab Karna, Karna's son Banasena came in aid of his father. On seeing Banasena, Bhima got angered as his own son Ghatotkacha was slain by Karna. Banasena challenged Bhima and soon attacked Bhima with mace. Bhima brutally but fairly killed Banasena in front of Karna. Bhima killed Banasena by hitting him several times on the head, chest and abdomen regions. Seeing his son's fate; Karna quickly picked up a mace and attacked Bhima. Still, in anger, Bhima beat Karna several times and almost took Karna to death. But Bhima spared Karna remembering Arjuna's oath of assassinating Karna. Bhima asked Karna to take his son's body to perform funerals and later fight with Arjuna. Bhima had a fierce fight with Ashwathama who repeatedly called him a coward just because he slew an elephant. They hurled a lot of arrows at each other and the battle was witnessed by Hanuman, who is the son of Vayu like Bhima and amsha of Shiva like Ashwathama. It was being witnessed by celestial beings. Then Bhima headed to kill Dussasana.