残ざん忍にん酷こく薄はく

• 残ざん酷こく

  Common word for 'cruelty'; 残忍酷薄 is a stronger, more literary yojijukugo emphasizing extreme heartlessness.

• 非ひ道どう

  Means 'inhuman' or 'outrageous'; 残忍酷薄 focuses more on cold-blooded cruelty.

• 残ざん忍にん酷こく薄はく

  Standard kanji spelling for this yojijukugo.

• 残ざん忍にん刻こく薄はく

  Variant spelling using 刻 instead of 酷; both are used.

A yojijukugo combining 残忍 (cruel) and 酷薄 (heartless, atrocious). The exact historical derivation is uncertain, but it is a literary compound used to intensify the sense of cruelty.