The Promutuus

From the word "advanced".

The original Promutuus are a newer race of humans that had once been entirely human. Over the past three decades, the Promutuus who have managed to free themselves from their 'Creators' have been starting and raising families, sometimes bearing Promutuus children of their own, sometimes humans.

History
For over a century, the people of Riveryne were desperate to gain an upper hand in the ongoing war against the Candeley. The Candeley came from over the water and brought with them armies from several friendly nations. The initial war was over land rights, as the Riveryne Nation was attempting to expand and absord the neighboring Demathendir.

Demathendir had been hosting several visiting emmisaries from Candeley during Riveryne's initial attack, and they had been lost for several years, hiding to stay alive. For over a decade, the country of Riveryne had informed the Candeleyans that the emmisaries had been murdered by their hosts, and their attacks on Candeley were on their behalf, as revenge for their trechery.

Almost two decade laters, with Demathendir almost entirely ruined, was Riveryne successful in absorbing the country.

The Trade
In order to develop those who would develop powers strong enough to battle the technologically advanced Candeleyans, the top military minds as well as their occult bretheren summoned a group of demons to make a deal:

At the sacrifice of their greatest treasures, they would have the ability to enhance humans to the point of having near-super powers. In the end, three entire families were sacrificed, as well as vision, hearing, self, and soul.

Those who remained whole were collectively given a leather bound book, to never be owned by any one of them. In it detailed how to get the exact ingredients for potions that they would use on their own citizens to force otherworldly power into them.

Promutuus
Not all who were experimented on develped their powers while 'in training,' even if the training took years. Because they were seen as useless, many escaped before being killed for being a waste of time and resources.

Many would reintegrate into society, using their powers alongside work if their powers permitted it. Others would use their power to cause destruction and strife wherever they went.