catastrophic (adj.)

• baneful
• black
• calamitous
• cataclysmal
• cataclysmic
• consuming
• consumptive
• deadly
• destroying
• destructive
• devastating
• dire
• disastrous
• fatal
• fateful
• grievous
• insurrectionary
• internecine
• nihilistic
• radical
• ravaging
• revolutionary
• ruinous
• self-destructive
• subversive
• suicidal
• sweeping
• tragic
• wasteful
• withering