The plan had worked.
A day after spotting Daniel's planet of origin, the three had followed their original plan, and had successfully entered the atmosphere without alerting the keeper of key, which if he had feld them, would have been able to report the presence of intruders way before the three could kill him.
The reason why they were forced to come here, and they couldn't simply teleport from another planet, was that they would need to go through a low level keeper of key.. And while Daniel was confident in convincing him to teleport them to his planet, Xargy had suggested that they didn't.
While it was true that they would have been able to pass through without being spotted by one of those individuals that opened the portals to other worlds, there was no assurance that they would not end up in front of somebody that could recognize them, and even capture them right away.