The Question and Answer section for Sir Gawain and the Green Knight is a great resource to ask questions, find answers, and discuss the novel.
Gawain's fiercest foe was the Green Knight's wife. She was an alluring, temptress.
He comes to challenge King Arthur.
Gawain begs to take up the boon instead, so the life of the king can be spared in place of a knight as weak and lowly as he.