And how is this cultivated? Trained? Are there Orders of those who can use Personae?

[Well, if it's a summoned creature, perhaps two can play at this game. Takes a moment to concentrate, keeping a tight rein on the level of darkness he exudes - it wouldn't do to have those pesky lightbearers rushing in on alert mode after all - and he reaches out with his heart to draw the darkness forth, summoning one of these to come play a bit.]