Tensei Shita Dai Seijo wa, Seijo de aru koto wo Hitakakusu ZERO: The Great Saint of Remembrance

The strongest knight meets a young saint with extraordinary power… In the Kingdom of Nave, the princess is six years old and born blind. She lives in the "Forest of Lent," far from the royal capital, because the king was worried about her being drawn into political disputes. But now the king dispatches Sirius, vice-captain of the Unicorn Knights, to "bring her home." (Source: Comic EarthStar, translated)