As Vaan made his way to the Great Hall, he thought a lot about his wood spirit, Emerald, who was the most pitiful among his contracted spirits.
Although he made a suitable living space for her in the Heaven-Swallowing Space, it wasn't the same as the earth and fire spirit spaces in which Topaz and Ruby resided. Without a wood spirit space for Emerald, she wouldn't be able to grow like Topaz and Ruby.
Furthermore, she would never be in peak shape.
As such, he added it to his list of priorities to achieve the Wood Spirit Body on his trip to the Great Ratholos Empire. It was said that all kinds of exotic and rare medicines could be found there. Perhaps he could find some magical plants and herbs with wood affinity-increasing properties.
Of course, another option was to dual-practice with Aeliana.
However, the benefits wouldn't be as great as the first-time experience. It would consume more time and effort the higher he raised his wood affinity through dual practice with her.