The stealth test had several phases. After all, some people were better at hiding in certain environments and situations than others. However, there was one element that excelled in all of them, Darkness! Many of the cultivators here knew how to use Yin Energy, allowing them to manipulate Dark Element. There wasn't a single one among the top contestants that didn't know how to do it. After all, even the Realm of Mortals had cultivation techniques that allowed one to use Yin Energy, let alone the Realm of Gods.
Yet, one thing was to use Yin Energy to manipulate Dark Element. Another...was to be born with an affinity to it! Roan's Shadow Steps could merge with the shadows. When he used Rean's Light and Divine Energy bending skill with his own experience, he basically ceased to exist as long as he didn't need to get too close to someone.