Although in the beginning Narada Muni appeared very angry and cursed them, at the end the two demigods Nalakuvara and Manigriva were able to see the Supreme Personality of Godhead, Krsna, face to face
SB Canto 10.1 to 10.13
Seeing the two sons of the demigods naked and intoxicated by opulence and false prestige, Devarṣi Nārada, in order to show them special mercy, desired to give them a special curse. Thus he spoke as follows.
Although in the beginning Nārada Muni appeared very angry and cursed them, at the end the two demigods Nalakūvara and Maṇigrīva were able to see the Supreme Personality of Godhead, Kṛṣṇa, face to face. Thus the curse was ultimately auspicious and brilliant. One has to judge what kind of curse Nārada placed upon them. Śrīla Viśvanātha Cakravartī Ṭhākura gives herein a good example. When a father finds his child deeply asleep but the child has to take some medicine to cure some disease, the father pinches the child so that the child will get up and take the medicine. In a similar way, Nārada Muni cursed Nalakūvara and Maṇigrīva in order to cure their disease of material blindness.