Augustus was shocked.
He had never expected Raven to make that kind of offer. He looked at him suspiciously, trying to see if he could spot any lies or schemes behind Raven's words but he realized that he had never been able to read this guy properly. And that somehow scares him.
Raven was a wildcard. Augustus knows that if he agreed to the offer, he might as well be pushing himself into another disadvantageous position. Yet at the same, this offer was so good that he can't pass it on.
Literally, the only reason why he's being suppressed right now is because he doesn't have access to the Forbidden Ultima Core's endless supply of power. Plus, he's trapped inside Raven's domain which makes him weaker. To even out the odds, he just needs the core.
Sure, he knows that there's a chance that Raven would go back on his word but if he's ready for it, he can prevent the situation from happening.
