Correspondingly, the two served as Odin's executioner and Darkseid's lieutenant during previous conquests, claiming territory in their names, but they were banished because of their desire for power and supremacy.

Source: https://www.cbr.com/hela-vs-steppenwolf-which-villain-more-powerful-dcu-mcu/

Goodness even cultivated an Earth-based school, where she effectively ran a fight club where she could select the best warriors to join Darkseid's cause.

Source: https://www.cbr.com/most-brutal-justice-league-villains/