Tristan sent a total of 7 people, with 5 of them being the formidable blue-tattooed warrior. The group should be strong enough to not die easily, and looked normal enough as a group of people who managed to retreat from a losing battle. Then, how did all of them disappear within one night?
This situation really baffled him, and at the same time, deeply concerned him. There is nothing normal about this. It's either his ability failed him or there was a higher power at play.
Thus with this new information, Tristan had to adjust, or even, completely change the strategy he planned.
Tristan quickly gathered all his companions at that moment, waking them up at dawn regardless of their opinion. After all, this matter greatly concerned everyone. They literally had no time to waste!
The moment everyone gathered, he immediately went ahead and interrogated Astrid and Scrall again. He had to know what could possibly make this situation possible.