The sound of flapping wings was so loud that it reached the city a few dozen kilometers away. It was completely ridiculous. They came like crazy, and the attractive mana was passing through the crystals; As soon as they arrived, they were poisoned. Each batch lasted only a few minutes and died completely. The perimeter was cleared in a few hours and about a day later they had the first area with about 500 kilometers clear.
The rune scheme was designed by Felix and Kayden together. They relied on a negative signal for mana capable of confusing spiritual senses, but the main means of camouflaging such a large area was using rune repeaters. This was humanity's greatest achievement when using runes.