Question: who is playing role of kalasur in qayamat ki raat
[{'answer': 'Nirbhay Wadhwa', 'provenance': [{'wikipedia_id': '57613410', 'title': 'Qayamat Ki Raat', 'start_paragraph_id': 16, 'start_character': 12, 'end_paragraph_id': 16, 'end_character': 26, 'bleu_score': 1.0, 'section': 'Section::::Cast.:Main.\n'}]}]