In the novel, Treyton was able to open his space because he was injured. He was injured badly and couldn't even take care of it; that's why blood flowed to the bracelet he was wearing. And all of it happened to Treyton near a biology laboratory.
Even though he knew that all of them might be in danger later, Luciel didn't say anything and just followed Treyton and the others out of the warehouse.
Treyton and the others were already stronger than what was written in the novel, so they should be able to deal with what they were going to encounter.
Besides, it isn't good to interfere with situations that could let Treyton and the others become stronger. If they don't encounter dangers, then they won't have additional opportunities to grow stronger.
As long as they don't die, Luciel doesn't care about the hardships they would encounter. The current time they were in is full of danger, so encountering hardships is only natural.