It was Ning's 6th day of training, where he was trying to convert the content of a glass of water into a glass of wine.
The test here was for him to do the conversion without messing up the glass itself. Liquids were notoriously hard to convert, given how flexible they were and how there was no numerical value that could be assigned to a liquid in opposition to solids which could be easily numbered.
Ning focused on the liquid and felt the energy within him grow enough that he was comfortable using it. Then, he willed the water to change into the wine he had tasted just moments earlier.
The water immediately took on a darker shade, turning more and more purplish as Ning focused his thoughts on turning the water.
In the past few days, he had come to understand a basic aspect of the magic in this world that was somewhat similar to what he had learned in another place.