One who or that which ruins, causing damage or destruction.

Someone responsible for a downfall or demise.

पतन का कारण

English Usage: Her reckless decisions made her the ruiner of her own career.

Hindi Usage: उसके लापरवाह निर्णयों ने उसे अपने करियर का पतन का कारण बना दिया।

To destroy or cause to lose value or quality.

To spoil or damage completely.

बिगाड़ना

English Usage: His behavior threatened to ruin the entire party.

Hindi Usage: उसका व्यवहार पूरे पार्टी को बिगाड़ने की धमकी दे रहा था।