Reborn as an Assassin's Apprentice (Light Novel) Vol. 2 by okiuta, Sinsora

Though our training grows harsher, I’ll do whatever it takes to survive my rebirth as an assassin apprentice. Just you wait! Using my unique skills and ability to think outside the box, I will drag my superior rivals down to my level. I will be no easy kill.
But my schemes to establish myself among my peers are interrupted by a competition: our cohort versus the ones preceding us—assassin candidates who have stood on the brink of death uncountable times. For the coming trials, to gain more strength, I’ll need to make decisions I can’t take back.