As many as you're willing to write down.

[ It will be fine. So long as Jon doesn't succumb to the absolutely bizarre urges that have started to haunt him— the desire to peel apart a human mind is exhaustingly familiar, but the urge to taste blood is trite and frankly ridiculous— there should be no ill effects. Secondhand nightmares are still enough to sustain him here. It's fine. ]

Beginning with those you think most likely to reappear. Anything we ought to have information on, for next time.