Need help using a Nightmare

[Brother MacLaren]

Pretty major battle coming up in my campaign; an old nemesis returns from Hell riding a Nightmare. I want to make this challenging, but I also want to use the monster's abilities fairly. It will be a 10-HD elite nightmare (CR 8) and the rider is a half-fiend orc Bbn10 (CR 12). The party is 5 PCs of about 9th level but has no single-classed PC caster (Rog4/Wiz5/AT1, Hex5/DD4, Ftr2/Brb7, Ftr8/DwD1, Ran9, and Clr7 cohort). Several questions here:

1) Does the Nightmare's continual smoke cloud obscure the rider's vision or grant concealment to the rider? I'd say "no" so that it makes sense for the creature to serve as a mount. Just have the rider sitting above the smoke cloud.

2) Does this sequence work? Rider readies to attack when within range; Nightmare uses Flyby Attack to moves to within range of foe (triggering rider's attack), attacks or uses ability, and then moves away. AOOs are not avoided, and charge bonuses are not gained, but because Flyby Attack does not require straight-line movement, the Nightmare can move behind cover afterwards (trees, buildings, etc.).

3) Does this sequence work? Rider readies to attack when within range; Nightmare moves to within range (triggering rider's attack) as its move action and then as a standard action readies Etherealness if it or rider is attacked (and so this would happen immediately before a PC's counterattack). AOOs are avoided because the creature only enters a threatened square, then uses a (Su) ability.

4) Astral Projection seems to be an EXTREMELY powerful ability; if I am reading it right, the Nightmare (and rider) can hide their bodies somewhere (possibly still in the Nine Hells) and just use their projections to attack. Can you project onto the Material Plane?

5) Why does this creature NOT have fire resistance?

I'm considering stripping out the Astral Projection ability, adding immunity to fire, and giving it max HP per HD. That, I think, is still a CR 8 Nightmare (since Astral Projection is so powerful). Otherwise, the Nightmare alone is a TPK, even at the un-advanced CR 5 version.

 

[Darklone]

Astral Projection is THE ability for a recurring villain till the PCs reach higher levels.

 

[frankthedm]

Otherwise, the Nightmare alone is a TPK, even at the un-advanced CR 5 version.

Ahem...

This spell functions like ethereal jaunt, except that you and other willing creatures joined by linked hands (along with their equipment) become ethereal.

 

[frankthedm]

3) Does this sequence work? Rider readies to attack when within range; Nightmare moves to within range (triggering rider's attack) as its move action and then as a standard action readies Etherealness if it or rider is attacked (and so this would happen immediately before a PC's counterattack). AOOs are avoided because the creature only enters a threatened square, then uses a (Su) ability.

A readied action can only trigger after one's own turn so this can't stop PC's AoOs & readies.

Ready
The ready action lets you prepare to take an action later, after your turn is over but before your next one has begun.

 

[Brother MacLaren]

A readied action can only trigger after one's own turn so this can't stop PC's AoOs & readies.

Right. AOOs would be avoided because none are provoked. Readied actions would not be avoided. Actions on the PCs' turn -- those devastating 3-or-4-attack Haste routines -- would be avoided. That (not AOO or readied) is what I meant by "Counterattack".

As to Etherealness, a literalist reading does indeed result in creatures without hands being unable to share in Etherealness or Plane Shift, as well as unable to cast Chill Touch. I wonder if that was an intentional design decision or an artifact of wording.

The tactics text for the Narzugon (FCII) references using the Etherealness ability, though nothing in the creature's stat block says it has a special ability to break the rules and benefit from the Nightmare's ability.