Facts About Nakul and Sahadev
Nakul and Sahadev are more loyal to Yudhisthir than anyone else. They don't share father or mother with Yudhisthir, yet they follow him everywhere and do exactly as he asks. They could have gone and ruled over Madradesh (their birthright through Madri), and lived a life of luxury and ease, but they stuck with their brother through thick and thin.
After the war, Yudhisthir appointed Sahadev as his personal adviser and Nakul as the supervisor of his army.
SAHADEV
Sahadev was expert with swords.
After Yudhisthira was crowned the king of Indraprasth, Sahadeva was sent to the south of India to annex or subjugate kingdoms. The warriors in South were particularly good with swords.
Some of the kindgoms which he subjugated were Matsya, Vibhishana (Ravana's brother), Surasena, Nishadas, Purava, etc.
He took an oath after the gambling loss of killing Shakuni and he does it at the 17th day of Mahabharata.
He also killed many prominent swordsmen like Rukhmaratha.
He is considered the Master of Astrology.
After years of Celibacy and meditation in the forest, Pandu once said to all of his kids that when he died they should eat his flesh. By doing so they would be blessed with great knowledge. But when Pandu died none of his son had the courage to do so. But Sahadeva saw some ants taking a piece of flesh from his fathers' body. He put that piece in his mouth and eventually got powers which he could never have imagined. He saw what all had happened (about Kuru and Yadava's, Bhishma's vow and everything that was past) and also about future (gambling loss, Mahabharta war, etc).
He met his cousin Krishna who made him vow to never speak of anything he knows. If anybody would ask a question he would always reply with a question itself.
As he knew what all was about to happen, he used occult sciences to show people how a small ripple leads to a disastrous or a good result. He learnt everything about planets and stars and thus predicted how certain aligning of planets or sun or moon or stars can change fortunes.
NAKUL
Son to Pandu and Madri and twin to Sahadeva, Nakul was famous for his good looks.
Nakul was sent to the west to subjugate kingdoms. It is said that Nakul had bought along so much gold and coins after subjugating kingdoms that Yudhisthir was compelled to distribute among his subjects. Every resident at that time was way richer than the richest in other kingdoms.
Nakul made a mark in the war by killing Karna's two sons who were extremely loyal and efficient kauravas.
Nakul was an expert in Ayurveda.
The credit of slaying the offsprings of all the 100 kauravas goes to Nakul. He destroyed the entire Kuru lineage.