The Demon Prince had made sure he selected the best candidate for his plan, after all with the amount of effort he had placed into this endeavor, it would be ridiculous if he did not go for the best.
Archimedes was truly unique, not because her talents were the worst among all Lightning Kirin that had ever existed like her coven had wrongfully assumed, it was in fact the opposite, she was the greatest genius in the Lightning Kirin coven, and the Demon Prince had likely waited for billions of years for the perfect candidate to be born before he took over her body and infected her bloodline root.
Every time Archimedes died, the benefits she gained were several-fold greater than what an average Lightning Kirin would receive, therefore the Demon Prince's talent and levels had been growing at an insane rate, reaching such levels that even if he had lived for a thousand more Eras, Ohrox would have never reached this height.