Usually female NTR villains tend to be big tiddy slutty gyaru.
So going by this story's logic, NTR-kun's fated one would be a big tiddy pure gyaru who tries, and fails to snatch the MC.
Did a demonic sword from the real world get transfered into the fantasy world or something?
Something like the IRL legend of the cursed sword Muramasa?
If this detail has already been explained, I apologize for my bad memory.
NotBochi activating her latent rizzler skills again.
This is like those shonen battle manga were the tension rises before the protag goes "THIS IS MY TRUE POWER HAAAAA!!!!"
latin chanting intensifies