With the time they fought hard to gain, the Blood Angels did two things.
Firstly, through personnel evacuation, and even by directly enforcing the Extinction Order without evacuation, they created a void wasteland.
As the Swarm passed through the barren land of these dozens of worlds, they received no supplies and consumed no biomass.
Even those planets originally responsible for stalling the Swarm, if the battle turned unfavorable, the Extinction Order weapons buried within the surface would be detonated by humans.
If they couldn't stop them, they would perish with the Swarm.
In doing so, they would also burn all biomass on the planets, leaving nothing for the insects to consume.
Of course, Extinction Order weapons are quite rare, and the number the Blood Angels hurriedly collected was insufficient for use everywhere.
So, they used them only on the most prosperous and populous worlds.
