By performing an asvamedha sacrifice and thereby pleasing the SPG, who is the Supersoul, Lord Narayana, the supreme controller, one can be relieved even of the sinful reactions for killing the entire world, not to speak of killing a demon like Vrtrasura

Expressions researched:
"The ṛṣis continued: O King Indra, by performing an aśvamedha sacrifice and thereby pleasing the Supreme Personality of Godhead, who is the Supersoul, Lord Nārāyaṇa, the supreme controller, one can be relieved even of the sinful reactions for killing the entire world, not to speak of killing a demon like Vṛtrāsura"

Srimad-Bhagavatam

SB Canto 6

The ṛṣis continued: O King Indra, by performing an aśvamedha sacrifice and thereby pleasing the Supreme Personality of Godhead, who is the Supersoul, Lord Nārāyaṇa, the supreme controller, one can be relieved even of the sinful reactions for killing the entire world, not to speak of killing a demon like Vṛtrāsura.

SB 6.13.7, Translation

The ṛṣis continued: O King Indra, by performing an aśvamedha sacrifice and thereby pleasing the Supreme Personality of Godhead, who is the Supersoul, Lord Nārāyaṇa, the supreme controller, one can be relieved even of the sinful reactions for killing the entire world, not to speak of killing a demon like Vṛtrāsura.