Though both were heretic cults, the Solar Sect and the Obliteration Sect had strikingly different traits, which meant that Duncan had to consider their "traits" when confronting the actions of the heretics.
The essence of the Obliteration Sect was to gain power and transform themselves through contracts with demons, and though these dark cultists explicitly worshipped the inscrutable Saint, their "deity"actually didn't respond to this relationship. Therefore, apart from the desecrated Transcendent power, the Obliteration Sect was still fundamentally a human group, with actions and limitations based on their identity as "humans"—no matter how loudly they shouted the Saint's name, these lunatics actually had little to do with the ancient gods.