Shi Lang sat in a closed room, there were no windows and no outlets. However, they were not suffocated, as he spotted a few oxygen dispensers laying in the corner. To prevent the enemy from getting better of them, he had told the team to cultivate.
He was recalling what happened to them, earlier when they had come out of the Arena, they crossed a small passage and suddenly everything became dark. The trick in this situation was that Shi Lang was unable to sense anything approaching him. They were not attacked by anyone, but the sudden blackout raised a lot of questions.
If he were to be trapped alone, he would have tried to massacre people and leave, but if he did that now, his team might be implicated with the legal procedures of this planet, they were not at the federation or at war, but they were on the peaceful world of the galactic council.