Durvasa was the son of rishi atri and Anasuya. He is known for his short tempered. As a sage he was not calm nature, he always became angry on little things. In whole Indian mythology, no sage was like him in Angry nature.
He had major indirect role in Samudra Manthan, Ramayana, and Mahabharata.
1. Ocean churning : According to Vishnu Purana, once sage Durvasa was roaming, Vidyadhari (nymph of the air) met him and gifted a garland of flowers. Sage Durvasa accept the garland and continued his wandering then he met indra riding Airavata on way.
Indra knew about durvasa's angry nature so he got down from airavata elephant and bowed. Durvasa pleased with indra’s this act so he gave the garland as a gift.
Indra mounted the elephant and put that garland on the head of elephant. irritated by smell of flowers Airavata dropped the garland. Seeing this Durvasa got furious and cursed indra to lose all wealth and power.
to regain all powers and wealth lord vishnu suggested a way of Samudra manthan.
2. Ramayana:According to uttar kand valmiki Ramayana, once yama the god death disguised as brahmin came to meet Lord Rama. He requested Rama to talking in private but in one condition that if someone disturb the conversation then he would have to die. Rama agreed and ordered lakshmana to gaurd the door that no one could disturb the private conversation between Rama and yama.
When lakshmana was gaurding the door, sage Durvasa appeared there and said lakshmana to tell Rama that sage Durvasa is come to meet him. Lakshman politely requested sage Durvasa to wait but sage Durvasa got angry and threatened lakshmana to curse Ayodhya.
To save Ayodhya, Lakshman disturbed the conversation between Rama and Yama. Lord Rama didn't want to kill lakshmana so he ordered Lakshmana to leave him for good, since such abandonment is equivalent to death, as far as the pious were concerned. Lakshmana then went to the banks of the Sarayu, and resolved on giving up the world by drowning himself in the Sarayu river.
3. Mahabharata : Sage Durvasa gave a mantra to Kunti that she can invoke any god and get bless of son.
By using that mantra she gave got blessed with son karna, yudhishthir, bhima and Arjuna.