Erdtree's favoritism. Something in the battle with the Fire Elden Ring Runes Giant changed Godfrey. He no longer had his will to fight, and that was when he lost the Grace bequeathed to him as it was to all others in the Lands Between. Queen Marika the Eternal had no choice but to follow the Great Will and banish her husband and lover.
Others began losing the grace of the Erdtree and became Tarnished themselves. Each was banished from the Lands Between but unable to die due to Queen Marika's tampering LOLGA.COM with the Elden Ring. Eventually, Queen Marika's firstborn was killed, leading to the Shattering of the Elden Ring.