He naturally knew that the Hundred Peaks Sect hadn't originally seized their righteous aura, but he insisted on saying so, with the aim to have a reason to capture a few people and, at the same time, to vent his anger.
Back then, their disciples from the Firmament Sect were indeed robbed by Cao Zhen. You seized treasures from our Firmament Sect disciples, so I'll just seize your disciples directly.
As for Cao Zhen being a reincarnated great ability?
So what?
Even if Cao Zhen is a reincarnated great ability and can break through into the Immortal Path Domain, how many years would his disciples need before they could enter the Immortal Path Domain?
Relying on Cao Zhen alone, how could they compare with the Firmament Sect?
Moreover, when the strong ones from the Immortality Regainment Realm awake, Cao Zhen would be even less significant.