Devibhagavatapurana 3.18.26

3.18.26

pratāpo mantrabījasya nānyaḥ kaścana bhūpate |
evaṃ vai japatastasya prītiyuktasya sarvathā ||

This is the influence of the seed mantra; it is not an ordinary acquisition. It is because Sudars’ana, with gladness and one-pointedness of his mind, meditated on his seed mantra, that he acquired the above powers; there is no doubt in this.