"The lowly demons are coming to attack? I'll destroy you!"
"They gain confidence from just a bunch of devils of hell? I shall show you the true terror of ancient demons!"
"Crush them all!"
The ancient demon kings led their armies to clash against the demons and devils from the Demon Realm.
The humans and demi-humans of the Human Realm used that opportunity to crush the demons. Meanwhile, the beast-kin and demon-kin from Northern Realm had to clash with the terrors from the Demon Realm.
Everyone had only two choices at that moment. Retreat or fight it out, but everyone chose the latter because their morale was unusually high. The newly formed alliance pioneered by Sacred Sakura and two other holy lands was the cause of that union.
The heroes would emerge in times of crisis. A particular 3rd Rank spear master used showed off his might far above his realm to wipe out hundreds of demons.
Sometimes you have to stop trying to force it, walk away and let your subconscious show you the way. Fill up on life for a while ^_^