looking for a spell or ???

[Thac0 Redeye]

My party has decided to camp for the night in the crypts of the BBEG (Strahd Vampire lord - Ravenloft) castle right after a big fight with Strahd and his Golem protector. The Golem died but not Strahd. I'm going to inform them that it is a dumb place to camp by: attacking with some ghosts and possibly affecting them with mummy rot. (i'll roll saves for it) I also want to have Strahd give them bad dreams that will cause fatigue the next day and possibly stopping them from gaining all spells back or something. ???
Perhaps some type of nightmare spell or ???

Help

ie. I did post another post yesterday titled "do I attack again?" this should provide more background

[sleepyphoenixx]

Doesn't Strahd need to rest too? He's a wizard iirc. You'll need to consider that when planning your attack.
And it's not really a worse resting place than pretty much anywhere else in the vicinity since Strahd has them watched anyway, assuming they take proper precautions.

Anyway, the Nightmare spell is core and does exactly what you want. Dream Casting (SpC) works similarly but offers different effects (shaken, charmed, rage and confusion).
If you want to get real nasty there's also Dreaming Puppet (HoH) which is basically unlimited-range Dominate Monster with a shorter duration, but it requires either the Improved Oneiromancy feat (and its 2 prerequisites) or emulating it with Limited Wish (it's only 5th level).