My Overbearing Senior Sister

To survive in this world, one must be prudent, impassive, and merciless while he can't challenge someone out of his level nor consort with girls.
Senior sister, he is just at Foundation Establishment Stage. Why would you bomb him with forbidden spells three times?
Senior sister, it's just bruises. Why would you feed me with Immortal Pills?
Senior sister, would you please stop pretending to be cute?