Karna

Bhima

After Adhiratha (the charioteer who raised Karna) entered the arena and Karna showed him filial respect, Bhima laughed and mocked Karna saying: 'O, he is after all only the son of a charioteer! Take up the driving whip then as befits thy parentage.' This cruel insult deeply hurt Karna, causing his lips to tremble with anguish. Duryodhana then defended Karna against this insult.

His earrings and armor

Indra disguised himself as a Brahmana and asked Karna for his divine earrings and armor. Despite being warned by Surya in a dream that this was Indra's deception, Karna could not refuse a request for charity. He cut off the earrings and armor with which he was born and gave them to the disguised Indra. In return, Indra gave him the Shakti weapon, though with the condition that it could only be used once.

It sank in the mud

During the final battle, as Karna's fated hour approached, the left wheel of his chariot suddenly sank in the blood-soaked mud. This was part of his destiny and the curses working against him. When he jumped down to lift the wheel, it wouldn't budge despite his great strength. This mishap left him vulnerable and ultimately led to his death when Arjuna struck while he was trying to free the wheel.

Duryodhana

When Bhima cruelly mocked Karna about his parentage, Duryodhana immediately came to Karna's defense. He angrily told Bhima it was unworthy to speak thus, arguing that valor is the true mark of a warrior, not birth. He praised Karna's godlike form and skills, saying he was worthy to rule the whole world. This defense strengthened the bond between Duryodhana and Karna, leading to Karna's lifelong loyalty.