Bhrigu

Sage Bhrigu was a great tapasvi, one of the saptharishis who helped the Lord in the task of creation. He  had mastered yoga and the art of Sanjivini Vidya. He belonged to the first manvanthara.  He came out of Lord Brahma's heart and was called Brahmamanasaputra. He established the clan that came to be known as Bhargava gotra. The sage came out of fire after Varuna performed a great yajna. Brahma, Agni and Varuna vied for him but the Devas supported Varuna's claim. As a young boy, he mastered Brahmavidya through severe penance. Once he conducted a yaaga to find out which among the Trinity was the greatest. He cursed Vishnu for killing his wife, and so, in his incarnation as Rama, Vishnu suffered from separation pangs. Later when Bhrigu was able to bring back his wife to life, he repented the curse and started worshipping Vishnu. In fact, it's interesting that Narayana became Bhrigu's son-in-law as he got married to Sridevi who was none other than Lakshmi and the sage's daughter.  While Bhrigu was known to be short tempered, he was also  merciful when the situation demanded. He brought back Jamadagni to life and later helped Parasurama to give up the Kshatra way of life. Bhrigu released heaven from the arrogant rule of Nahusha and restored it rightfully to Devendra.  The sage  did everything to preserve dharma and didn't spare even Agnideva once as he went against it. Brahmadeva had to intervene to ease the situation. Thus, Bhrigu led a full and useful  life  preaching the righteous way of life to the world.