Regret. The feeling that consumes a person when they encounter a negative situation and have knowledge, they could have done something about it. Regret was a fundamental concept to humans. To our kind even more so. Our {Fates} were our regrets made flesh.
Ragnarök, the end of the world of Norse mythology was unique among all the many different mythologies. Norse and the Asgardian lore were built around Ragnarök. Valkyries and Einherjar were all were created and trained for that final battle.
Yet if what I had already learned was true. Every single mythology on Earth was once a civilization of Reapers that got wiped out. This meant that despite knowing of their coming demise, the Asgardians were unable to escape their fate.