The Lullaby divine ability was still working to make the god of dreams lower his resistance. But the power of the subordinate god was nowhere near enough to make the god of dreams give up resistance completely.
What made matters worse is that the subordinate god is a divine being reliant on him to live. So he could easily shut down her existence.
He did so immediately. He gave a single order and let the divine fragment within her reject her existence. This caused her to begin dying.
The god of dreams was also dying. He realized that this was going to happen even if Legion let him go. Since Legion wasn't willing to let him go, he decided to try to escape.
He used the newly gained power from his authority to launch one final divine ability. The divine ability he launched was the Dream Wandering divine ability. This divine ability launched the only intact soul of his that hadn't been completely contaminated by excess divinity into the dream island of someone nearby.
