"While it wasn't the best mana generator. It was the second best. That was reason enough for the beasts to pay close attention to it. Just like how there were territories on the Blue planet, there were territories on Atlas.
And so, they couldn't casually take it. They needed a diversion.
The former leaders volunteered with their armies to cause the said diversion.
They happened to have a suitable reason, too. And that was a resource planet close enough to Atlas. It was originally not worth fighting the beasts for. But since they needed a diversion, they launched a surprise attack to claim it.
While it wasn't important to their side, it held significance for the beasts because the material found there sped up their cultivation. Not by much, but enough to matter. After all, at that level of strength, any increase is more than welcome.
Anyway, when they launched the attack, most of the experts on Atlas went to help.
