OOh, I may steal that exorcism.  I wrote these moves for my current PbP game:

Origin & Use of Ghost Tech

Gasoline evaporates over time.  Cars and bikes and generators were bolluxed. 

When you open your mind to the maelstrom, you can see human-like shapes  of energy and mist and what-the-heck-was-that out of the corner of your eye.

Eventually, some sick fucker realized that you could put those ghosts into a motor and bleed them dry.  Engines powered by ghost tech scream when they’re firing.  A substantial ghost will give you about a month’s worth of juice in a bike, two weeks in a car, or a couple days powering a modest-sized holding.

Some of the ghosts are tougher than others, we’re not sure why.  Maybe they were murdered or maybe they were just badasses in real life.  Luckily they can’t touch you unless your mind is open to the maelstrom.

When a ghost fucks with you, roll+weird.  On a 10+, pick two.  On a 7-9, pick one:
> You don’t take spectral harm (ap)
> You deal it 1+weird harm (ap)
> You shut down your connection to the maelstrom.[/li][/list]
On a miss, it deals harm and you’re still connected to the maelstrom.

When you try to trap a ghost in a haunt box, roll+weird.  On a 10+, pick all three. On a 7-9, pick one:
> You capture the ghost
> You don’t attract any attention
> You don’t get hurt
On a miss, your haunt box is empty, the ghost is mad, and every angry specter in the neighborhood knows where you’re at.

When you install a haunt box, roll+weird.  On a miss, you fuck it up and fry the ghost.  On a 7-9, you install it correctly. On a 10+, you install it correctly and optimize the engine; pick one:
> The ghost lasts twice as long as usual.
> The ghost is muffled and doesn’t scream.
> The engine can be turbocharged (take +1 on a related roll but the engine will die shortly)

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I'm still getting some feedback on them from the players so if anyone has ideas, let me know.  I've got a couple ghost threats coming together too.

I love this idea.  Some idle thoughts ...

Apprentice, while an essential concept, might be a little vague and advantage mechanics rely on the MC's careful attention.  Perhaps also give them mechanic where they are essentially a gang of 1, and also assist with your rolls?

OR write it as "You get "Apprentice" and two more Mentor Moves."

Stand Tall ... how often would you "hold steady" multiple times in a scene?  Perhaps make this a blanket +1forward for the scene?

Training Montage is fantastic idea.

Voice of Reason.  I think I'd like the miss to have more consequences...perhaps explicitly give MC an chance to make a hard move?  I can see coming up with some impromptu "gazing into the abyss" verbage and "the abyss in this case is the PCs Darkest Self."

Mentor Sex Move.... I think the sentiment here.  If you decide to change it along lines of arscott's advice, perhaps use "Oedipus/Elektra Complex" as inspiration?