ShadenSword

In a world where intelligent species are as many as stars observable in the night.There exists Guardians of humanity, The Wardens. The wardens were the protectors of the human clans and they were known as heroes. 

Heroes of what you might ask?,Well in this world of chaos,there was no race who were safe.Not humans,not dragons,not goblins.No race was safe from each other.Each race were at war at each other,either for resources or power,nothing was left.Everything was an excuse for war.This was the rise of the wardens.The wardens or otherwise the protectors of humanity would destroy any race who would try to extinct the humans,and they had powerful and awful ways of doing it. Just as time went on passing,Humanity lived in peace and so did the Wardens.

However this peace didn't last long, as the emperor of the dragon race made a breakthrough in his bottleneck,and made a peace treaty with the other races,  deciding to make an alliance and annialate the humans,since they were growing more arrogant and brewing with confidence thanks to the wardens.

Thus the war began,under the  command of the dragon emperor's rule,all the races waged war and ruptured chaos,the main goal:extinction of humanity. However humans weren't weak, especially the wardens,commanding the 5 elements

The Warden Of Flames
The Warden Of Tides
The Warden Of Thunder
The Warden Of Winds
The Warden Of Metal

All pulled through,even though they were overpowered by numbers they too overpowered by strength,thus beheading not only the dragon emperor but also destroying HALF OF ALL RACES IN THE WAR.

However the 5 wardens were totally worn out, inorder to achieve the impossible they had to do the impossible,they burned their ESSENCE to gain strength,which had a huge toll on their strength and soul. So inorder to revive their Mana,soul and essence they had to go to slumber for 100 years. Humanity knew that they're hopes were gone however they couldn't hold the inevitable thus they built the citadels to honor the 5 wardens and let them sleep.

Even though they were worried it was obvious,no races were soon to recover of what they had seen or lost.

The wardens made their promise to return and help humanity but finally after 100 years, Ashfall the warden of Flames is shocked as he wakes up to a peaceful era where all the races of the globe live harmoniously among each other!

What will Ashfall do in a world that he is forgotten. A world where he has no purpose. Will he finally rest peacefully.

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Yes, use of mana Is present in this world. So is spells, magic and also all kinds of races are present, from dragons to goblins to you name it.. 
Also it follows slice of life theme. 
Any other questions will be answered in the comment section under author's review.

Table of Flame Bound Warden

Table of contents

Volume 1