First of all, was extremely difficult to actually try and kill those sneaky bastards.
Secondly, each and every one of them that died, or to be more specific the blood flowing out of their bodies was actually conjuring towards a specific location.
One didn't need to be a genius to understand that something was wrong, and most probably it was something related to formations.
Still, the army couldn't just stop their killing otherwise they would be the ones dying, as for just capturing the enemy, who had the time to waste it like that.
In the meanwhile, more and more sneaky bastards appeared, only to die after killing one or two targets, and the blood gathered towards the same location.
The more blood gathered at the location, the bigger of a bad premonition the General and the Sun Empire's Army experienced.