After hearing Ron's reason for coming, Orion nodded to him. Though he still didn't trust him completely, looking at Ron's face, which appeared to be full of sadness, he sighed. Orion understood the desire to grow stronger and the pain of feeling helpless. He decided to give Ron a chance, hoping that his intentions were genuine.
Unlike him, Famir, and Ryfin, Ron wasn't a transmigrator and was likely just a kid of about fifteen years old. So, what had happened before in Aethelgard City could be explained simply as him being scared, which led to certain situations.
He realized that Ron's actions might have been driven by fear and confusion rather than ill intent, making him more inclined to give the young boy the benefit of the doubt.