Long after the Golden Age, it was still very early in the cycle of time. And long after the war between the Aesir and the Vanir, the wall around Asgard that the Vanir had razed with their battle-magic remained a ring of rubble, deserted, the home of eagles and ravens.
The gods were anxious that the wall should be rebuilt, so that Asgard would be safe from evil-doers, but none were eager to take the heavy burden of rebuilding on their own shoulders. This is how matters stood for some time until, one day, a solitary figure on horseback cantered over the trembling rainbow, and was stopped by the watchman Heimdall.
Kvasir is referred to as the “wisest of the gods” in 
Muspell is guarded by the giant Surt. Surt has a flaming sword and at the end of the world he will come and vanquish all the gods and burn the whole world with fire.