Hearing what Mo Xi said, Five of Clubs was shocked because he hadn't expected that the other Poker members were killed by his boss! He had thought Mo Xi was the one that killed them! However, he wouldn't doubt what Mo Xi said because Mo Xi's eyes told him that whatever she was saying was true.
Jing Mo Chen, Ji Zheng Yang, Qin Feng, and Zhan Bo Cheng were looking at Mo Xi as she interrogated Five of Clubs, and they were all stunned when they saw how well the interrogation went. They thought that they had to go in one by one to punch him down and then used all sorts of methods to get him to speak. Jing Mo Chen was angered because what Five of Clubs said probably meant that Shen Nan Kun was the boss of Poker! However, they don't have direct evidence!
When Mo Xi came out of the room, she immediately went into Jing Mo Chen's arms as speaking with Five of Clubs reminded her about the possible relations of her parents' death.