On this page of the Assassin's Creed Valhalla guide, you will find a walkthrough of the Of Fist-Dances and Sweaty Oaths side mission.
Rewards for completing the mission:
- 1 200 XP;
- 350 Silver;
- BBB Membership.
In the place marked in the picture above, you will meet a man who stands in front of the door to an underground crypt. If you have level 3 of Charisma, you can get into verbal fight with him (Flyting).
If not, you will find a crow's nest behind a small building - climb on it to get a clue. The road leads through the roof and then along a branch.
A sheet of paper was nailed to the tree and a password was written on it, which will pave your way to the interior of the crypt. Go back to the man and say the password, and he will invite you inside.
The underground crypt will turn out to be a place where illegal fights are organized. Agree to fight and the bruiser will assign you the first opponent. Win 3 fights to gain the favor of the fighters and complete the side task.
In between fights you don't have to heal yourself, because Eivor's health will be automatically regenerated when he/she enters the ring.