Rimuru becomes the new teacher for Shizu's students. However, having been summoned into this world against their will and facing shortened lifespans as a result, the children's feelings are complicated, and they're reluctant to accept Rimuru. So Rimuru proposes a series of mock battles with each of them to ascertain their abilities and allow them to let off steam.
Relative to the amount of energy 
within him, it's really inefficient.
مُقارنةً بكمّية الطاقة في داخله، هذا
غير كافٍ إطلاقاً
Comparado con su energía,
es muy ineficiente.
En comparación con su energía,
es muy ineficiente.
Apesar da quantidade de energia
dentro dele, não é eficiente.