Vápnthjófr saga

To explain the “Hopeless fight”-thing: In norse myths, it was said that fate was predetermined and impossible to change, meaning that in Ragnarök, the world would inevitably be destroyed and most gods would die, no matter how many warriors they brought to Valhalla. (The whole purpose of dead warriors going to valhalla was to get warriors for the final battle- They spent their days fighting and dying, only to be revived in the evening and feast trough the nights)