She was so busy that she didn't think about Arthur at all. To be fair, she wouldn't have bothered with him even if everything was going her way.
There is just too little to be gained from Arthur now that she knows that there is a restriction on his soul. The best that she can do is watch his every move. But that hasn't borne any fruit, so she has given up on him for now.
While the higher-ups of the sect were playing cat and mouse, Arthur was focused on the cultivator. After a year of dedication and hard work, he has finally reached the peak of the third mortal coil.
He exhaled forcefully when this happened. He had to because he felt filled to the brim.
The sensation wasn't entirely an illusion. It is similar to when he had a stomach and used to feel full.
He doesn't have a stomach anymore, but his life seeds have replaced his stomach and are also full right now, so he is feeling a sensation akin to eating too much.
