"Upgrading to Rank-A, I suppose the situation in this zone is even more dangerous than before." Xu Huo said, "Since you came in, you haven't encountered a full-zone plant revival. It's been seven days now, your records are clear, all the way along you haven't seen any traces of large-scale destruction of plants. Even if mutant plants grow rapidly, those old trees tens to hundreds of meters thick can't possibly recover in just a day or two, so the last full-zone wave must have been a while ago."
"If the upgrade wasn't caused by a shortening of the interval between full-zone waves, then maybe the scale has gotten bigger and the duration is longer."
"It's also possible a special mutant has appeared among the plants, capable of causing massive destruction in an instant. If that's the case, the timing of the full-zone waves might become unstable."
