Whether you've noticed or not, by defeating your first Hyldnir in hand-to-hand combat, you've entered the Hyldsmeet -- the great competition of Hyldnir against Hyldnir to determine who will rule by Thorim's side.
The Hyldsmeet is the reason why I was imprisoned, for I sought to partake in the competition but was far too old and frail to be a match for the Hyldnir.
If you're willing to listen, I've a proposal for you.
Rewards
You will receive: 74
Progress
Keep it down, the others might start getting suspicious.
Completion
It's settled then. You will compete in the Hyldsmeet and with my help you're restore the great Thorim to his rightful place.
Notes
Look at them... all they care about is outdoing each other.
Tell me about this proposal.
You see, Thorim is not like these harpies. He's a worthy being of near godlike stature.
That is, until his wif, Sif, was cowardly slain by his brother.
What happened then?
Thorim lost it. He lashed out against his most beloved allies, the frost giants.
That's one reason why to this day, this land is torn apart by the war between the Hyldnir and the Sons of Hodir... and why Thorim has exiled himself to the Temple of Storms.
You want me to take part in the Hyldsmeet to end the war?
What do I care if these she-wolves and the frost giants kill each other every day?
No, no... I want Thorim to break out of his stupor and rally all his allies to retake Ulduar.
The world will be torn asunder if he fails to accomplish this!