Reports of the mysterious missile barrage were all over the Pandamonium forum as well as the subsequent actions that were being taken by the Pandarens who were staying at the Outer Wall camp.
The Royal Zodiac Snake Soldiers who were supposed to be on guard had informed all their fellow comrades that were 'off duty' and many of them staying at Jin's Pandastic Hotel responded promptly to it, allowing the Royal Zodiac Snake soldiers to take full advantage of the current situation.
The higher ups in the Royal Zodiac Snake Command who heard of the attack and responded accordingly felt that this was Jin's work even though they were not at the scene, especially Hou Fei. Even though the General of the Entire Snake Command will allow him to get a few extra winks as the rest of his company go into action, he has decided to go with the flow as well. There was nothing more reassuring to have a leader paving the way for attack or supporting them.
