Hao Ren had no idea what the exact content of the conversation between Marcus and Veronica was, but he was sure that they would talk about the ancient guardian's background. It had nothing to do with conspiracy, but about situational alertness and thoroughness, which anyone in their positions would have.
The sudden appearance of the ancient guardian and his misfits as well as the world surrounding him had aroused suspicion. Even though the princess believed him initially, she was not a three-year-old; she was doubtful. But Hao Ren could not care less.
When Hao Ren discovered what type of enemy the mortal race in this world was facing, he knew that Veronica would treat himself as her own. In the face of the Chaos, all people of the World of Order were natural allies.
Not to mention that he carried more than 20 kg of sacred objects.