Rebirth in the faith of gray means that a person rediscovers faith and hope and regains vitality and motivation after experiencing difficulties, pain or disappointment. The gray color of this faith symbolizes the dark side of life, while rebirth represents emerging from this situation with new vigor and strength. Rebirth in gray faith is a positive attitude and choice towards adversity in life.
(He later formally said "Nan Nan" to her, thanking you for staying with him for the rest of his life)
Purpose: To save each other for love