Sisters-in-law, I’m Really Not Stupid Anymore

A brief description of the manhwa Sisters-in-law, I’m Really Not Stupid Anymore:

Feigning madness for five years, I turned the tables and slaughtered my enemies to reach the pinnacle! Then, in a moment of truth: it’s my turn to protect you all for eternity! A family of ten was brutally murdered, and seven beautiful women insist on marrying me? Show more