So my party encountered wraiths the other day for the first time and the Favoured Soul used Flame Strike, also for the first time. I was a bit stumped by the half "divine" damage as I've never seen it anywhere else. Is it positive damage? Has it been errata'd anywhere? I ruled to not allow the wraiths their 50% chance to ignore it as divine vs undead seems appropriate, but is there any RAW out there to support this decision, or is there another divine damage spell or effect I should be aware of when dealing with incorporeal creatures?
Relevant section of Incorporeal Subtype:
Even when hit by spells or magic weapons, it [an incorporeal creature] has a 50% chance to ignore any damage from a corporeal source (except for positive energy, negative energy, force effects such as magic missile, or attacks made with ghost touch weapons).
Relevant section of Flame Strike:
Half the damage [of the spell] is fire damage, but the other half results directly from divine power and is therefore not subject to being reduced by resistance to fire-based attacks, such as that granted by protection from energy (fire), fire shield (chill shield), and similar magic.