My Wizard Experiments Never Fail

The cheapest consumables in the Wizarding Academy are not potion materials, but new apprentices. A mistake in the proportioning will cause the blood to crystallize; a deviation in the summoning will drag the soul into the gap; a failure in the pollution detection will make the body unworthy of being left behind. On the first day that Linn was assigned to the seventh laboratory of the Black Tower, before the corpse of his former apprentice was cleared away, he was pushed in front of a petri dish that was sporulating. The instructor only gave him one sentence: "Reexamine it, or become its nourishment." Everyone was waiting to see him turn into the next puddle of pus and blood. But Linn closed her eyes and died ninety-seven times in her mind. The ninety-eighth time! The contamination stopped, the petri dish was silent, and a line of conclusion that should not exist appeared in the experimental record: [The sample survives and the experiment is completed. From that day on, there was a monster in Black Tower Academy. Others risk their lives on the truth. He just knows in advance which road will lead to death.