"You've known this much in just a span of a small amount of time?"
Jeremiah couldn't help but speak in astonishment as he heard the reports coming from Cesar. The other people who were merely watching couldn't help but be curious as well and give him high praise while evaluating his capability as a rookie.
As for what he informed them, it was all related to the incoming Nightmare they were going to face. The way he delivered his information even though it's only been a day since he had come here didn't sound right at all.
In fact, aside from going on a lookout and joining the meeting from time to time, there's no other situation where Cesar was able to move even deeper and gather this valuable intel.
This is why Cesar was prepared to give an explanation as to how he was able to gather this important intel... even if it all sounded like a bitter lie.