Useless
Ryu's actions had been extraordinarily subtle, so subtle, in fact, that most wouldn't have realized that he was looking for something, they would have only thought that he was following a map in his head.
After learning how to use his soul properly, many of the weaknesses Ryu had gained with the loss of his eyes could be made up with a combination of his Void Spiritual Sense and his Dao. Paired with the knowledge he had, even if he wasn't familiar with the history of this world, Ryu had a lot of skills that he could still easily apply.
And yet, Selheira had seen through him, so clearly, she was also a very skilled Ruin Master.
Truthfully, if it wasn't anyone else, this would have greatly put Ryu off. This wasn't because Selheira was hiding her skill. After all, they hardly knew each other, so why should she tell him everything she could do?