Luciel knew that all of them left the kids in their RV and only left one behind as their driver and guard because he remained.
So he still took them on top of the building because he planned on staying there for a few hours, as it was a good place to watch what was happening around the Sun Base.
It was also getting chaotic below because of the people that were finally waking up to check the situation around them.
Nathan and the others were trying to deal with all the people below as fast as they could, but some who had spotted their RV and the kids wanted to deal with the kids first.
A few indeed managed to get close, but they were all dealt with by Mark before they could do anything.
Aside from wanting to see what was happening around them, the kids also knew that it was better to stay with him so that they won't trouble the others who were focusing on their fights, so they readily agreed to join him.
