It was not only Xue Wei who was intrigued and tempted, but even the Vermilion Birds also wanted to get access to another element.
The Vermilion Birds had an elemental affinity with Fire, but that was the only elemental affinity they had access to due to their bloodline.
Currently, Xue Wei had an elemental affinity with Wood and Fire, but he was aware that it'd be beneficial for him to get the thunder attribute too.
The more elemental affinities that one had access to, the better one's fighting ability would be. Although the affinities could not be merged, one could change between them in a flash, causing problems for their opponents if that was what one wished.
Elemental affinities were unlike Qi. Where Qi was what determined one's strength, elemental affinity was split into initiate, mediate, and advanced layers as to where one's control over the element existed.