MTL - I Give the Female Supervisor a Fish Pond - Chapter 79 confusion

When a cold and crafty girl travels into the body of a foolish, man-crazy, young female aristocrat, what will happen?

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

A ritual gone wrong gave him the world's deadliest Class—now all he wants is blood.Zeth stole the most powerful ritual magic in the world from a mad cultist. A Class that's fueled by the blood of his enemies and human sacrifice. One that's illegal to use, punishable by gruesome death. And now that he has it, he's faced with a choice: hide away for the rest of his life from those who would hunt him down, or embrace the power, becoming the hunter to get revenge on the murderer that stole his friends' lives.For Zeth, that's no choice at all.His enemies have to die. And he plans to use every drop of blood, eldritch ritual, and demonic summoning he can to kill them.

An elder asked a young man if he wanted revenge for being humiliated by a strong man and disregarded by his master. The elder offers to pass his power to the young man, who is amazed to find centuries' worth of skill appear on his phone. The power is from the Heavenly Court, where users can borrow without interest for 30 days. The young man worries it might be a 'magic loan,' but the elder assures him that it is safe, as the daily interest is very low.Zhang Yu snorted coldly and closed the ad.