All living beings in all the planets of this universe, including the presiding deities of all the planets, are fully under the control of the Lord. They work like birds caught in a net, who cannot move independently.Śrīmad-Bhāgavatam 6.12.8
lokāḥ sapālā yasyeme
śvasanti vivaśā vaśe
dvijā iva śicā baddhāḥ
sa kāla iha kāraṇam
lokāḥ — the worlds; sa-pālāḥ — with their chief deities or controllers; yasya — of whom; ime — all these; śvasanti — live; vivaśāḥ — fully dependent; vaśe — under the control; dvijāḥ — birds; iva — like; śicā — by a net; baddhāḥ — bound; saḥ — that; kālaḥ — time factor; iha — in this; kāraṇam — the cause.
The difference between the suras and the asuras is that the suras know that nothing can happen without the desire of the Supreme Personality of Godhead, whereas the asuras cannot understand the supreme will of the Lord. In this fight, Vṛtrāsura is actually the sura, whereas Indra is the asura. No one can act independently; rather, everyone acts under the direction of the Supreme Personality of Godhead. Therefore victory and defeat come according to the results of one’s karma, and the judgment is given by the Supreme Lord (karmaṇā-daiva-netreṇa). Since we act under the control of the Supreme according to our karma, no one is independent, from Brahmā down to the insignificant ant. Whether we are defeated or victorious, the Supreme Lord is always victorious because everyone acts under His directions.