So...was that thing that Venersis went into/got trapped by something that got him BECAUSE he summoned the shit into the desert as a punishment for it? Or did he just decide to go in because he caused it all? Also it's really fucking stupid how this manga endlessly tries to make him into some noble badass when all he does is follow orders that he knows are wrong dozens of times, fail over and over, then finally commit desert warcrimes to try and win a war before losing yet again.
And it made no sense for Yulian to be like "yeah man if it'd been me I totally would have also caused mass death and destruction among civilians and warriors alike all over the entire desert, including my own people, just because I was pissy about losing". The entire series has been about how devoted he is to protecting the desert, all the people in it, and to following his code of honor.