Credits: Aserwarth; Tenshi; Teddy; Dan|Apple; Pizarro; BSE; Aragon
You must fight him to get Thorvald's vote in this quest. However, on the final portion, where he hits quickly, you may die and will respawn above the house with all of your items. Note that this monster changes in difficulty!
He will learn to defend against your attack styles, so you will have to change when he does so. His first few forms are easy to defeat. The second to last one you will have to use protect from melee to beat, and his last form you will have to use a prayer potion, after he drains your prayer, to fight him. Ring of Recoil and monkfish or sharks are recommended.
Another option is to use prayer pots and a few rings of recoil.
Your challenge awaits!