The creator of High Valyrian used on Game of Thrones– David J. Peterson, has posted the full translation of Melisandre’s prayer on his blog:
Zyhys oñoso jehikagon Aeksiot epi, se gis hen syndrorro jemagon. “We ask the Lord to shine his light, and lead a soul out of darkness.”
Zyhys perzys stepagon Aeksio Oño jorepi, se morghultas lys qelitsos sikagon. “We beg the Lord to share his fire, and light a candle that has gone out.”
Hen syndrorro, oños. Hen ñuqir, perzys. Hen morghot, glaeson. “From darkness, light. From ashes, fire. From death, life.”
This prayer was used by the red priestess to bring Jon Snow back to life in the second episode Game of Thrones season 6 [Home].