One could offer sacrifices to at most nine great entities simultaneously.
At that moment, the practitioner's life would immediately reach its end, possibly even incurring a debt of longevity that innocent future lives would have to repay...
Levi calculated. For humans, a short-lived species, it was impossible. Even for most longevity species, whose lifespans were several times longer than humans, it was no different.
For instance, members of the Blood Clan, the Dragon Clan, elves, the Amethyst Race, and others could not afford to use it frequently.
Moreover, this method of sacrifice consumed all of one's life until death, only to potentially elevate one's realm by a single level. The cost far outweighed the benefits.
Of course, if faced with a mortal crisis, one might consider using it as a last resort.
However, given Levi's disposition, such a life-or-death crisis was unlikely to ever arise.