A supernatural ability has a save DC of 10 + 1/2 HD + ability mod. A spell-like ability has a save DC of 10 + spell level + ability mod. The destruction save is not affected by what caster level it has.
A supernatural ability has a save DC of 10 + 1/2 HD + ability mod. A spell-like ability has a save DC of 10 + spell level + ability mod. The destruction save is not affected by what caster level it has.
In the SRD it says (under half-fiend special abilities)
Spell-Like Abilities: A half-fiend with an Intelligence or Wisdom score of 8 or higher has spell-like abilities depending on its Hit Dice, as indicated on the table below. The abilities are cumulative. Unless otherwise noted, an ability is usable once per day. Caster level equals the creature’s HD, and the save DC is Charisma-based.
Of course, although it says caster level equals the creatures HD this doesn't mean that the DC is affected by it; they don't include the save DC calculation but probably should.
However, that still leaves Blasphemy as instant death to everyone level 30 and below
Thanks guys, I stand corrected on the DCs of SLAs.
As Plane Sailing pointed out, that still leaves Blasphemy as a TPK spell no save (apart from SR) as caster level = hd.
I am actuallly of the view that I'll make Ashardalon a "1/4 fiend" and give him the additional ability bonuses and natural armour, but not the SLA's (or maybe only one - Horrid Wilting). After all, Quicken Spell Like Ability only applies to one spell now and each 1/2 fiend SLA can only be used once a day and Ashardalon will have most of the good ones on his spell list anyway.
This solves my CR problem for Ashardalon as well. A Great Red Wyrm is CR26. Applying the 1/2 fiend template would bring this up to CR29, which is a bit steep XP wise for an estimated 19th level party.
If I make Ashardalon a 1/4 fiend, I'll give him +1 on his CR to make CR27 which brings him back to the CR in the 3.0 module.
I'll probably compensate for his lack of 3.0 Haste and Quicken Spell Like Ability on all SLAs by making Pemoka an 18th level Bard.
If "your ... hit points ... remain the same" doesn't do it for you, how about "[polymorphed creatures] retain their original ...hit points...", from the DMG (errata)? (My emphasis.)
Will said:
Some believe it points to 'you use the HD of the character,
Personally, I don't much care for Bastion of Broken Souls. We abandoned it after the second or third session. It just didn't play terribly well, and was the worst kind of railroading, IMHO. Now, Lich Queen's Beloved, from Dungeon #100...now THERE was a module for high-level hijinks.
Personal recommendation: you've reached high-level. You may lean you chairs back and teleport about the campaign world. The DM reminds you that there is no smoking on the Elemental Plane of Water. You've reached 9th-level spells and +10 enchantment weapons. Time to let the players cut loose. IMC, the wizard regularly shape-changed into a Solar (until it got him into trouble with the real things). It didn't change much, other than grant him more mobility. His SLAs generally work out to be weaker than his actual spells. That pit fiend is mighty, tis true...but so is a maximized empowered sonic fireball with greater spell focus and greater spell penetration tacked on. Seen any Miracles cast lately? How about Gate? Seen what a 19th level fighter can dish out, if he enters melee?
BBOS problem, IMHO, is that it starts out by nerfing most of the PCs information gathering abilities, saddles the party with an obvious turncoat NPC who is supposed to rescue the party (bad, bad bad!) and join them, lots of railroading and fights that are unavoidable, and so forth. What's that? The Paladin wants to reason with
the celestials guarding the quarantined god?
Sorry about that, you can't. Combat's the only solution. What's that? The Bard wants to
try and reason with the God of Arts and his lilend followers?
Sorry about that, you can't. Combat's the only way to get what you want. What's that? Your cleric wants to
try and use divination, wish and miracle spells to get answers about the mysterious attacker, Dydd and the reason all of the souls are being destroyed forever?
Sorry about that, but you couldn't force the players into a series of three successive, mostly meaningless combats, otherwise. And on and on.
I would worry less about the combat aspects of Shapechange, and more about how frustrating a module BBOS actually is.