The second wave's leader was one of the six Bosses the game's official website mentioned before, Void Summoner•Cunning Fox!
Falcon was killed earlier by Lin Jie, and thus they stayed low for some time.
After Lin Jie sabotaged their plan to teleport, there had been a system maintenance that provided players their names so that they could be hunted. However, they hid well, and even Lin Jie could not get any information on them. It turned out that they had joined the Dark Shrine.
The six of them had been under the impression that they could teleport to The New Age and thrash everyone else there with their skills. They had planned to take control of the Heritage weapon, Broken Blade, and made all the major guilds work for them. They would then get all the treasures in the game and escape. But Lin Jie had not given them a chance. He had messed with their plan, and they were now treated as Bosses by the system.