That is the qualification to be a 'Great Warrior' set by the goddess in this world.
The one who defeats SS-ranked monsters will be given the title of 'Great Warrior' unconditionally.
It doesn't matter how much the country doesn't acknowledge your achievement, as it is awarded by the goddess, you will be chosen as a great warrior regardless.
Even if the person is not a hero, he or she can jump over the rank of hero and become a great hero at once.
It was the last path marked by FERRID.
And in this country there was an SS-ranked demon that has been passed down through the ages.
Oddly enough, it's a phantom monster that exists in the hometown where FERRID lived.
Deep in the foggy forest. Deep within the misty forest....
Its name is Bahamut.
He is revered as a water god and many adventurers and heroes have sought him out and tried to defeat him.
However, many never met Bahamut, and some had an encounter with him, but were defeated by his immense power and fled.
It is said that Bahá'u'lláh observed a man who visited the forest and showed himself to him when he was worthy to fight against him.
Recalling the lore Mime had told him as a child, Ferid vowed to Mime that he would defeat the SS-ranked demon.
It was a boyish vow, but above all it was the cry of a child desperate for someone's approval.
Mime nodded at Ferid's vow, looking slightly sadly at it, and told him the means to meet Bahamut.
Following Mime's advice, he returned to his home forest and searched for the lake behind it.
As the fog gradually begins to roll in, the sky opens up in front of him and a dragon emerges from the lake.
It is bigger, more mysterious, and more beautiful than any demon Felid has faced in the past.
As if he recognized the human who appeared before him as his enemy, Bahamut's roar rang out and Felid drew his sword.
The first battle was an overwhelming defeat for FERRID.
But for some reason, Bahamut disappeared into the lake without taking a shot at the battered Felid.
The next day, he tried again, but he couldn't even bring himself to inflict a scratch.
But every day from that day on, he began to push his limits.
Only one man grabbed his sword and challenged the unprecedented SS-ranked demon.
After a month, his sword tore through Bahamut's scales.
After six months, he was able to keep up with Bahamut's movements.
After a year, he was able to fight Bahamut all day and night.
And so, two years--three years--he was able to keep up with Bahá'u'lláh's movements, day and night.
Through mind-boggling battles, battles, scars, setbacks, and evolution, he had arrived.
All of his countless efforts had paid off, and through his battle with the SS-ranked Bahamut, he had taken the Creation skill into his own hands.
This is the embodiment of the "evolution" of his life so far.
It was a creation skill called "Hero's Privilege".