Vikarna is a figure in the Mahabharatha and Hindu mythology. A son of Dhritarashtra and Ghandari, Vikarna was a Kaurava and a brother to the crown prince Duryodhana. As such, he was a cousin of the Pandavas.
Vikarna is universally referred to as the third-most reputable of Dhritarashtra's true-born sons. Usually, he is also indicated as the third-oldest son, but in other sources, the "third-strongest" reputation remained and it is implied that Vikarna is just one of Ghandari's 98 children (after Duryodhana and Dussasana).
On completing their training, Droṇācārya asked the Kauravas to bring him Drupada as a guru dakshina. Along with the Hastinapur army, Duryodhana, Dushasana, Yuyutsu, Vikarṇa, and the remaining Kauravas attacked Pañcāla. They failed to defeat the Pañcāla army, whereupon Droṇācārya sent Arjuna and his brothers for the task.
Game of dice
During the infamous dice game of the Mahabharatha, Vikarna raised his voice against the game as a whole, and specifically, at the mistreatment of his sister-in-law, Draupadi. Draupadi having already asked the Kuru elders about the ethics of what had transpired, Vikarna echoed her questions and demanded that the questions be answered. Like they had been throughout the entire episode, wise persons like Bhishma and Dronacharya did not raise their voice.
In the silence, and depending on the version of the story, Karna later rebuked and taunted Vikarna for being ignorant and interrupting while elders were talking. Vikarna quietly replied
Sister-in-law's insult is an affront to the entire Kuru clan. If her questions are not answered, our line is doomed—Vikarna, 
On the fourteenth day of the Kurukshetra War, Arjuna attempted to navigate the sakatavyuha of Drona, in order to reach and kill Jayadratha before sunset. Around mid-day, Bhima, in an attempt to find and aid his younger brother, had pierced the sakatavyuha and was making progress. Duryodhana sent Vikarna to check Bhima's advance. Bhima, who had sworn to kill all of Dhritarashtra's true-born (100) sons, called Vikarna a man of dharma and advised him to step aside. Vikarna replied, that even knowing that the Kauravas would not win a war against a side with Sri Krishna on it, he could not forsake Duryodhana. Pleading with him, Bhima reminded him of the dice game, where Vikarna had defended the Pandavas and Draupadi.
That was my duty then, and this is my duty now. Fight me, o son of Vayu!—Vikarna challenging Bhima, 
Alas, O Vikarna, you were just and knew what was dharma! You fought in loyal obedience to the call of duty. Indeed this battle is a curse upon us wherein men like you...have had to be slaughtered.—Bhima upon Vikarna's death
Vikarna is somewhat comparable to Kumbhakarna from the Ramayana. Both feel that their older brother's actions are against dharma...but in the end, both of them ultimately fight for said brother. His parallel within the story is Yuyutsu. Yuyutsu also feels that Duryodhana's actions are wrong; however, he resolves the issue by siding with the Pandavas at Kurukshetra; Yuyutsu's equivalent in the Ramayana is Vibheeshana.
- Mahabharata by C. Rajagopalachari