The Explosion was an event that took place during the final battle of the Arawn Losstarot War and ended the Second Age. Kagetsu Aurelac de Maar Sul led the armies of the Grand Alliance to face the warlock Arawn Losstarot at Lea Monde. Kagetsu took the magic sword Krystallopyr, invested with the combined power of every living Andain, and used it to fight Arawn. Even so, Arawn still almost won. Kagetsu had to throw his own lifeforce into Krystallopyr to defeat Arawn, an act which shattered it and caused a huge explosion that rearranged the face of the world.
In his final moments Kagetsu used his remaining powers to spread the power of the Andain among mortals, thus giving birth to the Innate Abilities. Most major cities of the world were destroyed instantly in the Explosion, and continents themselves moved, causing drastic climate changes. New nations eventually formed on the ruins of the old ones: parts of Grandbell, Isaac and Verdane became Aison, Maar Sul and Scundia; Augustia and Silecia became Libaterra; Manster and Thracia became Remon; and the remains of Miletos became Yamato.