Gods defeated demons centuries ago. The demons have returned, but can the new generation of gods stop them?

It has been 800 years since the battle gods "Idaten", who boast overwhelming speed and strength, contained the "demons" who led the world to ruin after a fierce battle. "That battle" is now just an old tale in a distant myth. While the "peaceful generation of the gods," who have never fought since they were born, are out of peace, someone has revived the demons from a long sleep. Bring armed forces, wisdom, politics, conspiracy, whatever you can use. No-rule and no-limit three-way battle royale is about to begin.