On this page of Assassin's Creed Valhalla's game guide, you will find a detailed walkthrough of The Measure of a Norseman quest.
The Oswald's feast ended in disaster, but perhaps Eivor will still be able to teach the future king of the Vikings how to win Broder and Brothir (Valdis's brothers) over.
Rewards: 5 100 XP.
Find and speak to Oswald
You will find Oswald in the Elmenham port. During the conversation, Eivor will try to persuade the future king to pay back Brothir and Broder for insulting him under his own roof.
Next, Finnr will come and try together with Eivor to teach Oswald flyting so that next time he can bite back. The conversation will end with a fake battle between Eivor and the future king of East England.
Speak to Finnr
You will find Finnr on a small rocky island at the edge of the map. The man has already prepared the place for the fight between Eivor and Oswald.
The training with Oswald will last several rounds and Eivor will be unarmed. When the practice is over, you will move on to the next stage of this task.
Pillage Serpent's Landing
Your next task will be to lead the raid to the camp where Rued Clan warriors are stationed. Oswald will accompany you. He hopes that this way, he will be able to recognized by Border ant Brothir.
Fighting your opponents, do not forget that your main task is to burn the carts and crates with goods.
When all the enemies have been eliminated, talk to Finnr to complete this mission. You will receive 5 100 XP.