Complex sentence: Going to it, she finds the Grail and realizes she has a choice before her: let Gryylth continue the way it has, or she can become more than its Protector: she can become its Goddess.
Split into simpler sentences: Going to it, she finds the Grail and realizes she has a choice before her. She can let Gryylth continue the way it has, or she can become more than its Protector: she can become its Goddess.