Note: This lasts until you rent or die. It will not put a status effect on you.
From The Barren Butte, go 4sw3s to Grer and ask Grer poetry.
Go west and ask Berling poetry.
In order to get to Kvaesir, you may travel past some wardens.
Initially wardens are agg and will likely attack you as you enter the room.
Once you defeat four wardens, however, the fourth will heal you to full upon his death and they will no longer attack you.
Go e2n2e (stand) eds2e and ask Kvaesir poetry.
Wear Hagalaz and go 2wnunede.
This will put you 1 south of the Dokkalfar and their leader. Upon entering the room, 3 Dokkalfar will spawn and attack you.
They are fairly easy, but like to choke you and can knock you unconscious.
Upon defeating the last of the Dokkalfar, their leader will spawn and attack you. This mob is more difficult than the 3 previous mobs combined.
The leader will have a corroded silver earring and the flute that Kvaesir needs.
Get flute corpse, go swuwsds2e, and give flute Kvaesir. He will follow you.
Go 2wnuw and Kvaesir will be killed by Fjalar and Galar.
Stand (get the flute from his corpse if you want to skip the Dokkalfar next time) and ask Fjalar mead.
Go 2w2s to Grer. Drink mead (you must do it in this room) and ask Grer poetry.
You will spout out a bunch of poetry and Grer will now let you access Dvalin (you can ask Grer Dvalin to access him later during this run).
Give shards Dvalin and he will mark you with the rune spell to pass the two-headed eagles.