unfeeling russian

• заскору́злый

  hardened, callous, unfeeling, backward

• зачерстве́лый

  stale, hardened, unfeeling, hard-hearted

• толстоко́жий

  pachydermatous, thick-skinned, unfeeling, case-hardened, insensitive

• бесстра́стно

  impassively, dispassionately, unfeelingly, coldly

• безду́шно

  soullessly, heartlessly, unfeelingly, coldly, callously

• чёрство

  stalely

  insensitively, callously, heartlessly, unfeelingly