How can Ketephys have the Moon Subdomain without the Darkness Domain?

Question

So in Ketephys's entry in Inner Sea Gods he clearly is listed as having the Moon subdomain but does not have the Darkness Domain. How exactly would taking this subdomain work?

Answer 1

The only text I was able to find for eligibility was from the introduction of subdomains in the Advanced Player's Guide:

Each subdomain replaces a granted power and a number of spells in the domain's granted spell list. A cleric who chooses a subdomain must have access to both the domain and its subdomain from her deity. If a cleric selects a subdomain, she cannot select its associated domain as her other domain choice (in effect, the subdomain replaces its associated domain). Subdomains are treated as equivalent to their associated domain for any effect or prerequisite based on domains. If a subdomain has two associated domains, the cleric can only select the subdomain for one of her domains. Subdomains can be selected by Druids (except the metal subdomain) and inquisitors (if their deity allows it).

This would seem to imply that a deity that provides a subdomain without the main domain doesn't actually do anything, since eligibility checks for both the base and the subdomain. To my knowledge, the APG was written before there were any published deities that did this, so it is reasonable to declare that it was inadequately future-proofed and that an orphaned subdomian should do something.

Since we've already entered common sense rulings, an orphan subdomain should provide the non-replaced abilities of the parent domain because otherwise it would be missing significant amounts of content. I was not expecting to find an example of this being officially used. Most openly available sources of statblocks with cleric levels stick to the core deities, who don't have any orphaned subdomains. However, it happens that this situation comes up in one of the official adventure paths that I happen to have on hand. AP #90, The Divinity Drive, features a cleric of a deity that grants the Stars subdomain without the parent Void domain, who has also taken Stars as one of their domain choices. Their statblock (pages 56-57) includes both the save bonus vs mind-affecting and the domain spell planar binding alongside abilities specific to Stars.