Parshuram was thought to be the sixth incarnation of Lord Vishnu. He was originally named Ram by his parents sage Jamdagini and Renuka Devi. Parshuram was a skilled warrior, despite being a Brahmin because Lord Vishnu never planned the caste system to be hereditary. Caste system was something that Lord Vishnu and his incarnations never approved of and those who believe in any form of caste system have a special place stored in the hell for them.

Anyways, with the way he used to fight and perform austerities, Lord Shiva got impressed and gifted Ram a Parshu (axe) and Lord Indra gifted him kaamdhenu (magical cow) from the heaven. That's why, he is called Parshuram. One day, a king named Kartveeryarjun with his soldiers came to the abode of sage Jamdagini. Thus, lots of food was produced by Kaamdhenu and Kartveeryarjun got jealous and asked Jamdagini how much he could give to buy Kaamdhenu.

Jamdagini didn't want to give the cow because cows are considered as mothers and one never sells their mothers but Kartveeryarjun took kaamdhenu forcefully and threw some grains for the cow (grains were used instead of currency in ancient India). When Parshuram returned from the forest after his training, he found his parents crying.

He then went to the palace and killed Kartveeryarjun with his Parshu. Then, his sons came and killed Jamdagini and Parshuram got angry and killed them and in his anger, destroyed forty one evil Kshatriya dynasties. He then cooled down and realised that he had destroyed the respect and dignity of the Kshatriya caste and even the good kings were fearing him now. So, Lord Vishnu decided that his next incarnation would be someone who can re-establish the lost respect of the Kshatriya and that incarnation was Lord Ram.

Meanwhile, Parshuram used to teach warfare only to Brahmins. He taught warfare to Devratta (Bhishma) and he will teach warfare to Kalki, the next and the tenth incarnation too. Parshuram is still thought to be alive and only those who are pure at heart can see him.

About Karna, Parshuram was once sleeping while keeping his head of his disciple Karna's lap when a scorpion came on Karna's thigh but he kept quiet so that Parshuram won't wake up. When his wet blood woke Parshuram up, he was surprised that a Brahmin could take this much pain and immediately thought that Karna was a Kshatriya. So, he quickly asked Karna, "Are you really a Brahmin?"

Karna bowed down his head and shook his head in guilt. Then, Parshuram cursed him that he will forget all the knowledge Karna got from Parshuram because Parshuram wanted to teach warfare to anyone but a Kshatriya and he thought that Karna was a Kshatriya...