The current level of Ryu's Dao wasn't something that Lords could fathom. Blurring the line between animate and inanimate was far more powerful than the words to describe it alone suggested.
When facing an expert like the young man, he could even take a concept that the latter only vaguely held onto and make it as real as life itself in the target's body.
The fact that the young man thought it alone was enough. By the time he realized that he should be guarding his mind against Ryu, it was already far too late. The thoughts had weaved their way too far into his brain.
The irony was that it was precisely because Ryu was using words to do it that made it all the more impossible for the young man to extricate himself. He was stuck in a loop.