He was a devotee of LORD SHIVA and was so powerful that even the 9 planets called Navagrahas were over powered by him and rendered in active.The story goes that he was in the kingdom of the Lord but was cursed to take birth in the world and get killed in the hands of the Lord to attain salvation.
His action in carrying away SITA , wife of Sri RAMA, which resulted finally in his getting killed in the hands of Sri Rama, who was an AVATAR of Lord Vishnu but had to remain as a human being sans his supernatural powers.
Ravana's great-grandfather was Brahma, a deity. His grandmother was a demon. Ravana's father was a sage and his mother was a rakshasa - a type of demion So, he had both bloodlines
Lanka originally belonged to Ravana's half-brother Kubera, the Lord of the Treasures of Swarga. Ravana and his rakshasa allies demand Lanka from him, and Ravana and Kuvera's father Visrawas advises Kubera to give it up as Ravana cannot be killed by any celestial being. Ravana is thus made king of Lanka.
Emperor of the Three Worlds
Using his invulnerability and strength, Ravana conquers and humiliates thousands of kings across India, building Lanka's empire and dominion over the rest of the world.
Ravana also conquers the Yakshas led by Yama and his half-brother Kubera. Ravana invades the netherworlds, conquering many daitya, danava and asura races and making an alliance with the powerful Nivatakavachas.
He then takes an army of millions of rakshasas to conquer Swarga. Even the devas, headed by Indra, Agni, Vayu and Surya are forced to submit to the power of Ravana's army.
Ravana was born Dasagriva (One with Ten Heads) the son of the sage Visrawasa by his wife Kaikasi, a rakshasa princess. Thus he is thought to have been either a brahmin or a mix of the brahmin and kshatriya castes. The name Ravana (One of Terrifying Roar) was given to him by Lord Shiva.
While it is impossible to corellate the names of places mentioned in the ancient legends of India with modern-day towns and villages, the entirely obscure village of 'Bisrakh' in northern India claims to be the birth-place of Dasagriva.
Despite possessing aggressive tendencies as a young man, Dasagriva becomes an exemplary scholar of the Vedas and religious knowledge under the coaching of his pious father.
Emperor of the World, and Evil
After winning his boons, Ravana is sought out by the leaders of the rakshasas, who desire him to lead their race to power.
Conquest of Lanka
Lanka originally belonged to Ravana's half-brother Kubera, the Lord of the Treasures of Swarga. Ravana and his rakshasa allies demand Lanka from him, and Ravana and Kuvera's father Visrawas advises Kubera to give it up as Ravana cannot be killed by any celestial being. Ravana is thus made king of Lanka.
Emperor of the Three Worlds
Using his invulnerability and strength, Ravana conquers and humiliates thousands of kings across India, building Lanka's empire and dominion over the rest of the world.
Ravana also conquers the Yakshas led by Yama and his half-brother Kubera. Ravana invades the netherworlds, conquering many daitya, danava and asura races and making an alliance with the powerful Nivatakavachas.
He then takes an army of millions of rakshasas to conquer Swarga. Even the devas, headed by Indra, Agni, Vayu and Surya are forced to submit to the power of Ravana's army.
Violations of Women
Ravana's sexual prowess is important to note as it plays a critical part in his legacy and downfall. Even as a young man he shamelessly violates women, and blessed with awesome strength, becomes an immensely virile rakshasa. He is a master of tantric vidya, or magical sexual arts.
Although Ravana is married to Mandodari, the daughter of Asura Maya, he captures thousands of women from his conquests and maintains a harem of unparalleled size.
Ravana also violates Rambha, the queen of the Apsaras. He is thereby cursed that if he ever forces himself on a woman again, his heads will burst. This curse protects the chastity of Sita when she is his captive.
There is also a discussed prophesy in the Ramayana that Ravana had violated Vedavati, a young ascetic who was performing tapasya to win Vishnu as her husband. Ravana's actions cause Vedavati to immolate herself, but she pledges to return in another age to be his destruction. The Rishi Agastya explains that Vedavati was born as Sita, and she is the wife of Vishnu's Avatara, Rama, and the cause of Ravana's death