In the Wrath of the Druids DLC for Assassin's Creed Valhalla, Eivor gets to take a trip to the lovely land of Ireland. On this new leg of their journey, they will meet up with a previously unmentioned figure from their past, Bárid mac Ímair.
Bárid is a Norseman, just like Eivor, and also hails from Norway. In fact, he is Eivor's cousin, and since his landing in Ireland, he has become one of the petty kings of the large island. Also since last seeing his cousin, he has had a son, prince Sichfrith, who is his heir, however, this apple has fallen far from the tree in terms of immediate temperament.
As stated in this codex entry, he is a rebellious teenager, and the first time the player meets him is when Sichfrith is openly disrespecting his father during a big feast. Things get so intense that his father, dear old Bárid, must walk away from the scene lest he loses his own temper while debating heavily with his only son and heir.
What's more, when the player steps in to remind the prince of his place, and that one should not disrespect their own father under their roof, Sichfrith turns his harsh words upon Eivor. The cocky youth dismisses the player's words, regardless of the dialogue option chosen, and claims that he could beat them in an old fashion brawl. At this prompt, the player is given the option to accept or refuse the one-on-one bout.
Should You Actually Fight Sichfrith?
Short Answer: Yes
Not only is Sichfrith a belligerent brat at this point in the story, but he is also a true-blooded viking and these two factors mean that he is relentlessly stubborn. He will not yield to words, regardless of how reasonable and measured, therefore other actions need to be performed so that he takes Eivor seriously.
This means that yes, one should definitely fight Sichfrith and teach him a lesson in humility and respect. When the player selects the option to initiate the one-on-one fistfight, gamers will find that Sichfrith is more bark than bite, despite being a 17-old ball of aggressive energy. Most gamers should have no problem putting the young man in his place, however, the smaller fighter is quite speedy, so light attacks are ideal to avoid having one's own attacks interrupted.
After the solid thrashing that the Wolf-Kissed unleashes, Sichfrith will immediately change his tune and will from then on act much more amiably with Eivor, and, by extension, his father. Solving a conflict with words is often the better course of action, however, when confronted by someone who simply won't listen, sometimes a bit of rough-housing is required.