In respect to this, is R Hllor the many faced god?
R'hllor is the god of fire, light, life. The Many Faced God is the god of death. Inside the temple there are statues of the deities of death worshiped by the followers of all known religions. There is no statue of R'hllor inside, it's a place of peace, darkness and death.
Secondly, what is Arya Stark doing with the many faced god? Arya, in Bravos was training to be faceless man(woman), serving the many faced God. In the books, Arya served in the house of black abd white, learned about poisons, gathering information by developing those 'espionage' skills. She is still learning and has already been given her first assignment.
Considering this, is the lord of light an old God?
R'hllor, also known as the Lord of Light, the Heart of Fire, the God of Flame and Shadow, is a prominent god in Essos, but has only a few followers in Westeros, where he is more commonly known as the red god. His symbol is a fiery heart.
Is the Knight King the Lord of Light?
Combine the two abilities and the Night king becomes the most powerful supernatural in the current day Planetos. He is nothing short of a god himself. He is the Lord of night, the dual of the Lord of light. The former brings death while the later gives life.
