high level help

[Razz0putin]

I'm running the 3rd part of reverse dungeon where the players play about 15th level monsters. I as the DM am running characters of about equal level that are besieging these demons and undeads in their homes. The problem is that I've never played characters at quite this high of a level so I don't know where to begin with tactics for these "heroes". So since we have some people here who've played these sorts of characters I call upon your expertise what sort of tactics/preporations do you do/take when taking on demons/undead at this level.

p.s. I've used 3rd ed. rules for this 1rst ed. module (not always successfully)
the monsters the players are playing are a bound Glabrezu sans gate & dispel magic, ghost wizard, a minor death as per the deck of many things, a wraith scion. The attacking adventurers have access to a large local church and all the resources that would suggest
any help would be appreciated

 

[Dr. Strangemonkey]

How many heroes are going to be in the party?

How good an idea of what they face are they likely to have and how long have they been preparing?

Regardless of the above answeres, one of them has to be a paladin.

 

[Piratecat]

That's a tough job!

I recommend that you use heroes with relatively few choices. In other words, a sorcerer instead of a wizard, a barbarian instead of a fighter.

 

[Razz0putin]

There are 5 adventurers (the max # for a word of recall the party cleric can do) in the heroes party (well 4 now the last delve didn't go so well )
They've faced the monsters twice
they prepared for about a month were'nt ready for so much resistance, fell back came back a week later with anti undead and extraplaner stuff memorized and ready.
The "heroes" are led by a Clr13/Ftr4 there's a Wiz13/Ftr1 there's dwarf paladin 12th and a 10th level half-elf druid. I need to refill this 5th spot with something aroung 10th level.
thanks for the help I'm just not used to this level of stuff