I felt like I should follow up on this.
The Harbinger
The Harbinger is a charismatic individual, a false prophet or demagogue. She may be the high priestess, the iron fist of decency, or the object of worship itself. The player characters must engage him and his converts in social thrust-and-parry (or try to undermine him indirectly).
Some possible Aspects for a Harbinger:
Rejoice, for he is come
Every citizen a fanatic, every child a pawn
Only a fool or a villain would speak out against our savior
The Conduit
The Conduit is the chink in the armor, the subtle sickness. It is the village that used to be neighborly and functional, but has become self-serving and pragmatically cruel. Helping others is just not worth it. Take care of your own, and that particular group seems to shrink all the same. Keep to the old ways, and who really remembers how old those ways really are. The Conduit is not a person, but a ritual, a mannerism or even a subtle physical characteristic. It is the thing which ties a poisonous community together.
Some possible Aspects for a Conduit
What's your business, Stranger?
The silences speak volumes
Your ways are not Our ways
The Mystic
The Mystic is an intellectual villain. She makes the wise eager to surpass her or curry favor with her, while the fools strive for the appearance of wisdom. Her weakness is some secret, hidden among enticing knowledge and flashy trivia. Even those who would work against her is snared by hidden lore and erudite debates.
Some possible Aspects for a Mystic
Wisdom is always hidden
Words, not deeds
Calm yourself! You're being irrational!
The Horseman
The Horseman never comes alone. He'll bring an army of cut-throats and brutal marauders. People are slaughtered or broken, villages burned, and societies reduced to survivors huddling in fear. Fighting the Horseman may require a stomach for bloodshed, or maybe just the strength of ones conviction and refusal to cower.
Some possible Aspects for a Horseman
Droves of warriors
Compassion is a luxury we can't afford
No house is home, no fortress safe
The Fool
The Fool is an affront to existence. It is a sexless creature that sees the world as an endless series of maddening set pieces, and works towards reshaping things so that they fit its alien aesthetics. It will often be found at the center of a warped area, full of lethal beauty and fairy tale logic. It's servants may once have been human or have simply sprung fully formed from its inhuman imagination.
The Fool is hard to kill or defeat. Its life, like everything else about it, works according to fairy tale logic. Its heart may be hidden in an egg, inside a duck, inside a deer, inside a great linorm. Maybe you need to shape your most cherished memories into weapons against it.
Some possible Aspects for a Fool
All your assumptions are wrong
Maddening aesthetics
This awful place keeps changing!
The General
The General marshals all the Grey Emperor's troops. She plans attacks, devises insidious strategies to take over the world. She even directs and deploys the other lieutenants at times. As such she is usually not the sort of villain you confront directly, as she is the strategist behind legions or wild and warped soldiers, and even if you do she'll most likely have a plan up her sleeve, and reinforcements over the next hill. Or a dagger when you sleep in your tent.
Some possible Aspects for a General
That was just the vanguard...
Just as I had anticipated!
The pain of war can not exceed the woe of aftermath
The Void
This is the lieutenant nearest to the Grey Emperor. He is the Emperor's physical form. We say 'he', but the Void does not have a gender. He is as inhuman as the Fool and as cunning as the General. Getting rid of the Void will in no way be easy or obvious, as he resides as much in hearts and minds as in that iron fortress at Oblivion's Throat. There must be an alternative to the Void, as well as a means of defeating him. Else he will just be reborn, rebuild and rise again another day or aeon. Possibly through his downtrodden underlings.
Some possible Aspects for the Void
The overlord's castle is a maze of horrors
Ye liveliest awfulness
This is where we live now