I'm thinking of implementing the
Deadeye Devotee and
Thought Thief archetypes. These are official Paizo archetypes that were originally intended for inclusion in Chronicle of Legends, but got cut due to space issues and
released as a blog post instead.
The kicker is, they're archetypes for
prestige classes, namely Arcane Archer and Arcane Trickster, which is weird. Are there any other prestige class archetypes? I went looking for examples to study and came up blank.
If these are truly the only two prestige class archetypes, it may be simpler just to make whole new classes rather than try to force the archetype system to work with prestige classes. The original prestige classes are from the CRB and aren't marked as non-copyable, so I could just copy those and adjust them appropriately.