Shion was a《Legendary Hero》born with all the six Arcanas of elemental magic:

The Wave Arcana [Fire & Water]The Moon Arcana [Light & Darkness]The Nest [Life & Death]The Cloud [Gravity & Air]The Tower [Earth & Aether]The Great Passage [Time & Entropy] He was humanity's strongest warrior, the last bastion of hope protecting mankind from anything that threatens it.

However, during the battle with the 《DemonLord》, Shion's magic was stripped away from him. They were personified into actual people, sentient beings that can now think for themselves, and Shion, having now lost all his magic and his memories, is but a former shell of his past self...

In an ideal world, these six Arcanas owe it to Shion to continue fulfilling the duties of a Legendary Hero. It's the least they could do in memory of their master...

But Shion's Arcanas are none of that. They are selfish, they are tired of working together, and now, they want to finally settle the question that hasn't been asked: which of them is the strongest Arcana.

This was the DemonLord's plan. Great power is never a good thing if it can't be controlled, and the Arcanas have great power indeed. All six can destroy the world if they so wished. If two of them clash, the result would be devastating.

Although the six part ways at the start of the story, the world is a small place... It's almost destined that they will fight each other, and when that happens, no one, — not the world military, not even Shion, — can stop them anymore.

This is the story of a world that lost its prodigal hero. It is a story of a ticking timebomb, of the six inheritors of Shion's magic, thinking the whole world is theirs for the taking... Of the new, amnesiac Shion, getting entangled in the mess that is the Arcanas and learning more about himself in the process—

...This is a story — of how the world will end, and who will be the one to end it.