Fëanor is a very famous character in the Silmarillion. He was the leader of one of the Houses of the Noldor, and he was the one who brought the Noldor to Middle-Earth. Many feel that he rebelled against the Valar unjustly, though others claim he was provoked: his father was killed, after all.
I am of the opinion that Fëanor started out good, but slowly deteriorated into what is called an antihero now, and ultimately became a villain before he reached Middle-Earth. To offer some background, he was the son of the oldest ever elf, Finwë. While living in Valinor, he was the greatest smith of the realm, and was envied by many. He made the palantiri, or Seeing-Stones, and of course the Silmarils. But he was too proud of the work of his hands, and when Morgoth poisoned the Two Trees, and Finwë was killed at Formenos, he called the Valar captors, and stirred the host of the Noldor. He and his sons swore an oath to ‘Pursue with hatred and vengeance anyone, Vala, Elf, or Man as yet unborn, angel or demon or any creature great or small,that the world should bring forth until the end of days, who should keep or hold of take a Silmaril from their possession.’. He led the Noldor to bargain with the Teleri for their ships, but when Olwë denied them passage, they slew the Teleri, and stole their ships. This was known as the Kinslaying, the first battle in Aman. He then proceeded to strand his brother in the middle of the frozen ocean, burn the stolen ships, and force his sons to fulfill their terrible oath even after realizing that it was hopeless.
The main argument saying he was provoked is the death of his father. I wish to bring to your attention that he was not driven by revenge: his father is not mentioned in the oath, it is only the Silmarils. He is driven by greed. When he swore this oath, his deterioration to greedy villain is complete. He had many chances to repent, but he chose to deny them. He cannot be considered a hero: everything he does he does out of greed and stubbornness.