Jaya- Mahabharat

परशुरामः - Parashurama

Fiercely, Amba walked out of Hastinapura, and decided to avenge the singlemost person she considered responsible for ruining her life.
Bhishma.
She went and called out to several kings, present at the Kashi Swayamvar, and urged them join and defeat Bhishma. She had ruined her life, her love and her desires. Since several kings were envious Bhishma's prowess and powers, she hoped that everyone would join her. But several declined out of fear. Whoever little did join her, were defeated in an instant by Bhishma.
Angry and failed, she began to wander. A group of passing Rishis saw this lady, distraught, worried and roaming. Out of compassion, they asked, that what is it that she is finding, to which Amba replied, "Revenge. Against Bhishma"
The Rishis looked at each other, and then said, "then there is only one entity in this whole world, who can maybe give you that"
Amba's face lit up, "Who!"
"Parashurama" They said, and went away silently.
Now, though we have seen earlier about the deeds of Parashurama, I shall brief it again here.
Parashurama is considered the 6th Avatara of the 10 Avataras of Lord Vishnu (protector, Narayana, as seen in the first chapter)
He was born to Rishi Jamadagni, and was a severe austere Brahmin boy, but had the build tougher than the most powerful kings. That said, once an arrogant king Sahasrabahu (one with a thousand hands) visited his father's ashram with a huge army. The Rishi (Parashurama's father) fed the entire army from his humble household. Surprised, the king asked how did he get so much food? The Rishi replied it was the cow Kamadhenu (the desire-milking cow) who would give whatever he asked.
The king immediately, out of greed and amaze, demanded that the cow be given to him. The Rishi explained that the cow is hoky and divine and ought to be kept in religious, and austere conditions. Irked by the dare to refuse him, the King cut the head of the Rishi, murdered Parashurama's entire family and took the cow away by force.
Parashurama, meanwhile, was out on a penance. He had pleased Lord Shiva (destructor) and received the Parashu (axe) from Lord Shiva himself, and Lord Shiva also trained Parashurama in all martial arts.
When he returned and found out all about it, Parashurama became seriously afflicted. What does the monarchy think of itself? It has no rights to treat subjects like their slaves of will.
And so Parashurama set out to avenge Sahasrabahu and bring justice.
But all the kings of the entire land were Sahsrabahu's allies.
Parashurama, single handedly took down the entire army, allied forces, allied kings, and even Sahasrabhu himself, and killed and plundered the entire monarchy class. Women and children were forgiven. But as a new generation grew, they again wanted to defeat Parashurama and punish him.
Another war, and Parashurama washed the world clean of the tyrant monarchs. 21 times, he defeated and slayed the world clean of monarchs (Kshatriyas) and thus he is said to have made the world Nikshatri (devoid of Kshatriyas).
Slowly, times changed, and good kings took over, apologized to Parashurama. Parashurama went over to hill Mahendragiri and set up his Ashram where he would take Brahmins, Rishi putras, and deities as students and train them in martial arts if they wish.
Parashurama, being an incarnation, is also considered Chiranjeevi (deathless until the creation us destroyed) and is also far and wide famous for his anger, and thirst for war. But long before Mahabharata, when Parashurama met Lord Rama, his anger was pacified and he became soft towards Kshatriyas also.

When Amba went thus aggrieved to Parashurama, he listened to her story, and became disheartened indeed. "Indeed Amba, you have been wronged. My Shishya (student) is your guilty"
"Your Shishya, Bhagavan? (Lord)" Amba asked.
"Yes. Devavrata is my shishya. I myself trained him"
Amba became mildly concerned. But Parashurama, sensing her concern, said, "Worry not Amba. That fact will not make me any lenient towards him. I will bring justice to you"
Amba became delighted, and they both set out to punish Bhishma.