Short answers, pulled from the story.
The Sakha Republic, officially the Republic of Sakha (Yakutia), is the largest federal subject of Russia by area, covering over 3,083,523 square kilometres in the Russian Far East along the Arctic Ocean. It is the world's largest country subdivision, slightly smaller than India but larger than Argentina, with a population of around one million.
The towns of Verkhoyansk and Oymyakon in the Sakha Republic hold the record for the second lowest temperatures ever recorded in the Northern Hemisphere, behind only Summit Camp in Greenland. Oymyakon recorded its extreme low in February 1934, and Verkhoyansk recorded its lows in 1892 and 1885. Yakutsk, the capital, regularly averages below -35 degrees Celsius in winter.
The Sakha, also called Yakuts, are a Turkic people who migrated to the middle Lena River from the area around Lake Baikal, likely between the 9th and 16th centuries. They were pushed northward by the Buryats, a Mongolic group, and brought the pastoral economy of Inner Asia with them. They displaced earlier Tungusic and Paleosiberian peoples, most of whom were assimilated into Sakha society by the 17th century.
The Sakha Republic produces 99% of all Russian diamonds and more than 25% of the diamonds mined in the world. The Mirny diamond mine is among the most important sources. The republic also holds large reserves of gold, oil, gas, coal, silver, tin, and tungsten.
The last major battle of the Russian Civil War was the siege of Sasyl-Sysy in the Sakha Republic. It involved a White Guard detachment led by Anatoly Pepelyaev, who had arrived from Harbin hoping to capture Yakutsk and restart the civil war in Siberia. After the Red forces captured Amga and lifted the siege, Pepelyaev retreated to Okhotsk, where he was arrested. The last White Guards in the north of Sakha surrendered by the end of 1923.
The olonkho is the ancient epic tradition of the Sakha people, historically performed as an oral and improvised art form. It was first written down by leaders such as Platon Oyunsky in the early Soviet period. UNESCO has recognised the olonkho as a masterpiece of the oral and intangible heritage of humanity.