Although Shi Xiaobai had suffered defeat all night long, he was constantly improving. He went from suffering an abject defeat after one strike to the point of him finally being able to survive dozens of strikes.
This was a very apparent progress which Sunless noticed. She could not help but reveal a faint smile. It was a very beautiful smile, but short as well. It was fleeting.
Shi Xiaobai felt somewhat regretful, but his regret was a result of the short night.
Although he was able to end in a stalemate with Sunless over dozens of strikes eventually, that was him using the Beginner Sword at the Crest of Perfection against her using Beginner Sword at the Exemplary Mastery realm.
The Beginner Sword was after all a basic sword technique. There weren't many variations or tricks, but Sunless had used her own sword insights to open up a gap between them.