Seeing Lady Tyra's behaviour, Drayce could guess that this shapeshifter was not lying. In fact, judging from the way Lady Tyra reacted, he could guess he was someone important to her, someone like family and not just a simple 'friend'.
Just like what she did with Seren, Lady Tyra also made sure that Aureus' body was clear of black magic as well.
She looked at Drayce with moist eyes, her gaze filled with gratitude towards the young king. "Thank you so much for saving him, Your Majesty."
Lady Tyra could not help but be thankful to Drayce. She had raised Aureus for the past twenty or so years, and he was like a real son to her. As much as she cared for Drayce, she cared for Aureus the same way.
Drayce didn't even know Aureus but he still chose to save him despite being suspicious of him.
"He claimed to have been saved by my mother in the past," Drayce said as an explanation.