As the battle was reaching its conclusion slowly but surely, Li Yan and others were observing from outside the tent with their guards lowered than usual. They knew that the enemies were rogue bandits, who had mistaken them for a merchant caravan and had walked into their deaths. Li Yan and others could clearly see that the Li forces were winning by a landslide and couldn't imagine that a threat was lurking in the shadows.
Only Shijie knew of this unknown threat but he was sick in the first place, and feeling such instinctive fear creeping into his spine for the first time, he was petrified in the place and couldn't even move a finger.
While the hidden person was patiently waiting for a perfect opportunity to shoot off the arrow with precision and finish the job in one single lethal strike, they focused all their inner Qi on the arrow, making it even more dangerous.