I love reading the stories of Purana. Besides their religious taste, the characters are all of different flavors even when they are viewed as purely human. Ramayana was written in Tretayug and Mahabharata in Dwapar. I'd point out to some interesting facts to be more specific, certain characters from Ramayana, who were reborn in Mahabharata as different characters. I'd list the character in Ramayana as (a) and their reincarnation in Mahabharata under (b):
1. (a) Shri Rama (Ramayana): He was the king of Ayodhya in Ramayana and the slayer of the demon Ravana. Rama is considered to be one of the ten incarnations or avatars of Lord Vishnu. His motivation to be born in the earth (Martya) was to free it from the evil demons (asuras).
(b) Shri Krishna (Mahabharata): Shri Krishna was the king of Dwaraka in Mahabharata. He is also considered to be one of the ten incarnations or avatars of Lord Vishnu. He was actually Shri Rama reborn in Dwapar yug. Shri Krishna quotes:
"Yada Yada Hi Dharmasya
Glanirva Bhavathi Bharatha,
Abhyuthanam Adharmaysya
Tadatmanam Srijami Aham'.
Bhagavad Gita (Chapter IV-7)
"Whenever there is decay
of righteousness O! Bharatha
And a rise of unrighteousness
then I manifest Myself!"
He performs a similar role here slaying many demons like Kamsa, Shishupal, Dantbakra. He plays a major role in the success of the Pandavas in the battle of Kurukshetra.
2. (a) Ravana and Kumbhakarna (Ramayana): Ravana was the main demon character in Ramayana who carries off Rama’s wife Seeta to seek revenge for Surpanakha, his sister. Kumbhakarna is his younger sibling, who stands by him. Both of them are subsequently slain by Lord Rama in the battle that followed. But all was not bad of Ravana. In fact he was a very lerned Brahmin who was extremely talented. He had a full grasp of the Vedas, besides being an excellent musician who played Rudra Veena. He was a very powerful archer as well.
(b) Shishupal and Dantbakra (Mahabharata): Shishupal was the king of Chhedi in Mahabharata. He was born with a pair of extra hands. It was said, that Shishupal would be freed of those extra limbs when his slayer baby sits him. Incidentally it happened to be a young Sri Krishna. Shri Krishna vowed to forgive 100 sins of Shishupal before slaying him. Shishupal grew up to be an arrogant king who demeaned Shri Krishna at every opportunity. Ultimately he was beheaded by the Lord by the Sudarshan Chakra (the disc). Dantbakra, his sibling, met with the same fate.
The story goes on like this: Both these pairs of characters were actually incarnations of Jay and Vijay, the two guards od Swarga (Heaven). They were cursed to be born as demons for three births when they didn’t allow a few sages to enter Heaven. They would be freed from the curse when Lord Vishnu in His different avatars, would slay them. In their first birth, they were Hiranyakashipu, and Hirannakshya. Hiranyakashipu was slain by Lord Vishnu in the Narashima (Man-lion) avatar, while Hirannakshya was slain by the Varaha (Boar) avatar. In their second birth, they were born as Ravana and Kumbhakarna to be slain by the Rama avatar of Vishnu. In their third birth, they were born as Shishupala and Dantbakra and were slain by the Krishna avatar of Lord Vishnu.
3. (a) Kaikeyi (Ramayana): Kaikeyi was the second wife of Kind Dasharatha, the father of Shri Rama. In the pursuit of making her own son Bharat, the king of Ayodhya, she forced Dasharatha to send Rama to an exile of 14 years. Dasharatha died broken hearted and Kaikeyi faced a curse, which she underwent in her rebirth.
(b) Devki (Mahabharata): Kaikeyi was reborn in Mahabharata in Dwapar yug as Devki. Here because of her curse, incidentally she had to stay away from her son Krishna for 14 years (the period of Rama’s exile), before he return to free her after slaying Kamsa.
4. (a) Kaushalya (Ramayana): Kaushalya was the eldest wife of King Dasharatha and the mother of Shri Rama. She was a very caring mother and equally loved all her step sons. She was heartbroken when her son was sent away from her for 14 years. But Lord Rama promised to be with her even in their next incarnation.
(b) Yashoda (Mahabharata): Kaushalya was reborn as Yashoda in Mahabharata. She became the fostering mother of Shri Krishna who lived His first 14 years of life with her. He kept His promise in this way.
5. (a) Lakshman (Ramayana): Lakshman was a half-brother of Shri Rama who was always by His side. He forced himself into exile along with Shri Rama. He helped Him to recover Seeta from Ravana.
(b) Balarama (Mahabhatara): It’s believed that Balarama is a reincarnation of Lakshman. Balarama was the half-brother of Shri Krishna and was His best friend.
6. (a) Baali (Ramayana): Baali was the powerful king of apes and ruled Kishkindhya. He had a boon to get half of the strength of his adversary and hence was undefeatable. He had a misunderstanding with his sibling Sugriva, and drove him out of the kingdom. Sugriva took refuge in Shri Rama. Shri Rama killed Baali from behind, while he was engaged in a combat with Sugriva.
(b) Jara (Mahabharata): Shri Rama had committed a crime by killing Baali from behind. He even offered Baali life. But Baali had by then understood his sins, and chose to die in the hands of God. Shri Rama promised Baali, that he would have a chance to seek revenge. Baali was born as an archer and hunter Jara in Dwapar yug. Jara lived on shooting birds in the forest. Shri Krishna was resting in the forest when Jara, thinking His beautiful feet to be a bird, shot at them. Shri Krishna left the world, thus keeping His promise to get slain by Baali in his next incarnation.
7. Hanuman (Ramayana and Mahabharata): This was a character which appeared in both the epics. Hanuman was an ape and a very faithful servant of Shri Rama. He took a big part in Ramayana helping Shri Rama to recover Seeta from Ravana. Hanuman lived a very long life to spread the message of Shri Rama in this world. In Dwapar yug, Shri Krishna eventually meets his disciple after keeping him waiting for long. It’s also said, Hanuman was present in Arjun’s banner during the war of Kurukshetra. He helped Arjun in the battle after asked to by his Master Shri Krishna.
8. Jambubant (Ramayana and Mahabharata): Jambubant was bear who helped Shri Rama in his war with Ravana. He was also a disciple who, like Hanuman lived a long life on earth to spread His message. Shri Krishna also met Jambuban in Mahabhatata (Dwapar yug).
9. (a) Seeta (Ramayana): Seeta was the wife of Shri Rama who was carried away by Ravana in Ramayana. She is considered as an ideal woman, who gave everything for her husband.
(b) Rukmani (Mahabharata): Rukmani was the incarnation of Seeta in Mahabharata. Rukmani had a much happier life than Seeta in Ramayana. This was perhaps the result of her sacrifices in Treta yug.
That is all for now. I’d continue writing on this topics.