Their job is to manipulate thoughts, emotions and impulses to put you into a slow/transitional state, triggering releases of energy from your field which is siphoned off by psychic or technological means. Lingering emotions such as fear and guilt tend to produce a slow and steady bleed of energy... While anger and sexual orgasm produce short, highly concentrated bursts.
Being a child of the light or of the dark means having the ability to deflect, absorb, create and destroy energies. Some can do one or do all obviously with different goals in mind. A child of the dark seeks to feed on energy and use it to bolster their own powers.. They manipulate the environment around them, they create adverse conditions and exploit unwary people. They come from all backgrounds, creeds and nationalities and you cannot detect them until it's too late.
The hierophant sits in glory surrounded by his followers, they clamor over each other and revel in their shame, they degenerate to their basest function, lusting for one another and desiring to offer up a sacrifice of energy to their master who guides them beyond the gates of ecstasy. Yet, while he watches them perform..he is absorbing their energies, he's cycling his power and in his meditation transcending beyond his human limitations.