This mystery can be found on the southern island of Asgard, northeast of Litamiotvitr. As you approach the location shown below, you’ll hear a man screaming the name of Havi. He wants you to free him from Asgard, and send him to Hel so that he can be with his wife.
Speak with Motull
When you speak with the man, named Motull, you’ll have two dialogue options:
“Your arrogance will be bought with blood.”
“There is nothing for you in Helheim.”
If you choose option 1, you will need to fight Motull. If you’d rather not fight him, choose option 2 to persuade him to stay and complete the mystery without a fight.
If you choose to fight Motull, it won’t be much of a challenge. He essentially fights like a Woe-Bringer enemy, with a large two-handed axe to begin with, which he will wield slowly and predictably. You can parry all of his slow attacks with the two-handed axe relatively easily, aside from those which begin with a red rune aura.
When you bring Motull down to around 50% health, he’ll throw his axe at you, so you’ll need to dodge or roll out of the way when he does. At this point he will begin to wield two hammers, with which he’ll be much swifter in his attacks. He will use the hammers to chain attacks, often resulting in a surprise kick which could catch you off guard if you’re not ready for it. Parry or block if you’re quick enough, or just flank Motull with a dodge to hit him from behind or at the side. He doesn’t have much health, so you should bring him down quickly.
After the fight you’ll need to revive Motull, who will then resign and accept his fate. This completes the mystery.