Nothing is known about Nyida Sanggye (nyi zla sangs rgyas), the First Getse Getok Tulku (dge rtse ge tog sprul sku), other than his role in the origin of the powa ('pho ba) transmission for which the Getse Getok incarnations are known.
His hagiographical account tells only that he was a treasure revealer (gter ston) and a specialist in powa, the practice of transferring consciousness at the moment of death. The transmission is said to have originated with a previous incarnation as the Minister of Religion for King Tri Songdetsen's (khri srong lde btsan). When the minister was near death, the King sent for Padmasambhava and presented him with a golden disk, representing the sun, and a silver one, which represented the moon, as a maṇḍala offering. After giving him the powa instructions, Padmasambhava predicted that he would be reborn as a holder of the teachings.
Nyida Sanggye is considered the First Getse Getok incarnation, a line that began when Getse Pema (dge rtse pad+ma, 1745-1813) was identified as his reincarnation. The incarnation line was based at Simdha Dzogchen Monastery (srib mda' rdzogs chen dgon), a branch of Shechen Monastery (zhe chen dgon).
Bibliography
Tshe dbang 'gyur med. 2011. Srib rdzogs chen dgon gsang chen bkra shis chos gling gi byung ba rags tsam brjod pa drang srong bden gtam. Lha ldan sprul pa'i gtsugs lag khang: Tshe dbang 'gyur med.