The Federation had already sent a few groups of people in to search for their whereabouts. However, the changes in the ancient battlefield were too intense. Many people died there, but no one was found. In the end, the Federation basically gave up.
When Ouyang Lan came, the Federation's army was only guarding the ancient battlefield and was no longer sending anyone in.
Ouyang Lan had originally wanted to wait for An Sheng to come, but after the sudden blood storm in the ancient battlefield, Ouyang Lan was afraid that her father wouldn't be able to hold on any longer. Without having the luxury of time to wait, she decided to lead her men into the ancient battlefield.
Based on the current information, as long as the blood rain didn't hit the skin, there shouldn't be too much of a problem. However, the strangeness of the ancient battlefield was far from that.
