The Blood Magic Debate
DéDannan Blood Magic was a blend of Arcane, Divine, Primal and Psionic Magic. It altered bloodlines quickly and precisely instead waiting for breeding and random mutation. It was a hotly contested subject among gods and mortals of The Golden Age. Nadúir and Croí felt it was wrong to interfere with The Cycles of nature. Compléasc knew it would help his favoured species advance to great heights of perfection but knew it was incredibly risky.
Blood Magic Benefits
Blood magic brought The Ancient DéDannan close to their heights of The Mythic Age. While it could not grant A Divine Spark it made them almost perfect mortals. The Ancient DéDannan's mental and physical abilities were vastly superior to other species. They lived for centuries didn't succumb to infirmity, corruption or disease. They gained spontaneous psionic and sorcerous powers and were unmatched wizards and clerics.
The Blood Blessing
However, The Ancient DéDannan in their haste and hubris broke Compléasc's rule against using hybrid mutations. These have always been the province of Athrú. They used them to accelerate their bloodline improvements and it worked tremendously well. Then Cealg whispered some helpful advice from Athrú; a virus could apply the improvements to all The Ancient DéDannan at once. The ambition of the DéDannan was always their greatest flaw. Initial tests proved miraculous and they named it The Blood Blessing to allay the fears of the people. When used, it spread bloodline improvements to the entire DéDannan species in just a few months. It provided vast improvements to all The Ancient DéDannan. Perfection was close at hand and even Compléasc, despite his anger, admitted it was impressive.
The Blood Plague
The Blood Blessing did indeed spread great improvements to most of The Ancient DéDannan. But after some time, as Compléasc feared, the widespread mutations began to destabilise. They continued to spread and mutate with wildly unpredictable results. Many were unaffected or slightly improved but most were transformed horribly. It created oni, fomorians, yeti, ogres, and others beyond counting. It ruined the Ancient DéDannan, they fell from grace and began to decline. One of the most common strains was the DéDannan Guardian.
It was formally renamed The Blood Plague and known to all as The Scourge. It leaders hid the worst mutations, blamed other empires and made empty promises of an imminent cure.
Athrú cackled with glee. This was his greatest achievement!