Record of Potential Disciples: I Turn F-Rank into SSS-Rank!

Struggling teacher Xu Che is mocked by the entire school for only accepting F-rank trash. Until the master system awakens, he is shocked to discover that three despised F-rank female disciples are actually hidden SSS-rank powerhouses! One evolves instantly after eating a fierce pig leg out of hunger, another hides purple celestial thunder inside her, and the third grows stronger the more she eats. The whole school waits for him to be kicked out, but he turns F-rank students into the strongest team with a single move. Stop pretending, you are all SSS-rank!