The winged skeleton was insistent on remaining a skeleton. Although his soul flames had already evolved into the level of a Spirit King and were capable of remodeling his own body into any type of powerful spirit, he was still very resistant to such an idea.
He did not wish to forget the years he spent as a skeleton, which were tough and full of life-threatening dangers every day. Back then, he was only a low-level skeleton. Even though he had a pair of wings, it was not much of a factor. Many spirits of the dead also possessed the ability to fly, so his wings did not give him much advantage.
It was only when he met Saleen that he understood that he could be useful in his own way.