Can a vampirized but devout cleric of Pelor avoid losing spellcasting?

Question

Situation: The cleric of Pelor was held against his will, and forced to become a vampire. Pelor is known for especially hating the undead, but also "urges his followers to remember that excessive attention to things of evil can blind one to the truly important things: compassion and goodness" as Wikipedia says. The cleric is also repentant and remains devout.

In the monster manual, vampires are "always evil", however it is noted that "always [alignment]" simply means it is exceedingly rare to find a creature of [not that alignment]. Let's say the cleric is able to stay within 1 alignment step of Pelor by some miracle (pun unintended).

Questions: Does anything happen to his spell casting? Will he need to find a new deity that's willing to accept undead followers?

(Inspired by the question https://rpg.stackexchange.com/questions/82431/implications-of-cleric-becoming-undead, which was closed as unclear.)

Answer 1

If the cleric were truly repentant and devout, he would arrange for a resurrection, and immediately destroy himself. However, let's say he was on his way to do just that. I know of no RAW reason that, say, a True Neutral vampire cleric could not receive spells from Pelor - Libris Mortis, the Monster Manual, and Complete Divine don't say anything about the issue. It will be challenging, however: from page 15 of Libris Mortis:

newly converted undead are often entirely ignorant of those deities now most deserving of their service ... however, like calls to like, and no unifying force is more potent than the divine call of undead gods to their potential flocks.

The book doesn't go into any details, so it is the DM's job to decide what problems an undead worshiper of a "mortal" god encounters.

There is an article in Dragon magazine #346 that suggests the origin of vampires was clerics of Pelor that turned away from him to study black magics:

By cursing Pelor's name and turning from him, they made it so they could never look upon him again without being destroyed. The fable points out that this destruction is a result of the undead turning their hearts and souls from Pelor, not because of his wrath.

The story tells that Pelor would use his power to redeem them if they asked. This story explains why undead suffer from the sun's light, but if they would turn away from evil, Pelor would welcome them back into his illuminated graces.

So the DM has a ton of plot hooks for a vampire Pelorite.

Mechanics of a vampire cleric of Pelor

Vampire clerics are severely hampered, regardless of the god they serve:

Vampire clerics lose their ability to turn undead but gain the ability to rebuke undead. ... A vampire cleric has access to two of the following domains: Chaos, Destruction, Evil, or Trickery.

Answer 2

The cleric could be initiated into the true faith of Pelor.

That is, the vampire cleric could learn that Pelor is actually the Burning Hate, a neutral evil deity pretending to be a lawful good deity. Of the domains available to vampire clerics, Trickery would be ideal and Destruction & Evil would also both work well.

The only problem with this approach is that the Burning Hate is believed to hate the undead, especially vampires, because they cannot properly suffer from sunburn & skin cancer (vampires die before they can suffer enough to please the Burning Hate). Of course, given Pelor's deceptions thus far, he may be willing to accept a hated vampire as a follower in exchange for the services it can provide, just like he's willing to pretend to be good to reap the benefits thereof.

Answer 3

While you are correct that "Always Evil" generally means that it's just very rare to see a non-evil version of the creature, there are further clarifying rules in the "Vampire Characters" section:

Vampires are always evil, which causes characters of certain classes to lose some class abilities.

This makes it pretty clear that vampires are an exception to the "always doesn't really mean always" rule of alignments. Vampires always have to be evil, and newly turned vampires have their alignment changed. Since Pelor requires his worshippers to be Good or Neutral, a Vampire can't be a cleric of Pelor and retain spellcasting.