Lord Gwyn's Firstborn

Lord Gwyn's Firstborn, also known as the God of War, is a mentioned character in Dark Souls.

Lore
Lord Gwyn's firstborn, the God of War, inherited the sunlight from his father, Gwyn, the Lord of Sunlight.

As the God of War, he wielded the Sunlight Blade and Great Lightning Spear miracles and wore the Ring of the Sun's Firstborn. He had respect only for arms, and nothing else.

His foolishness led to the loss of his deity status, and he was expunged from the annals. He left his Sunlight Blade miracle on his father's coffin, perhaps as a final farewell. Today, even his name is not known, but the old God of War still watches closely over his warriors.

Covenant
The Warrior of Sunlight covenant is closely related to Gwyn's firstborn and, assuming the player meets the correct requisites, it is possible to join by praying at the Sunlight Altar, located in the Undead Parish, or by talking to Solaire of Astora, a fanatical member.