Kṛṣṇa has many potencies: parāsya śaktir vividhaiva śrūyate (Śvetāśvatara Upaniṣad 6.8). The description of Aghāsura was disclosed after one year. Some act of Kṛṣṇa’s potency must have been involved. Therefore Mahārāja Parīkṣit was very curious to know about this, and he requested Śukadeva Gosvāmī to explain it.