Hi Hethra,
What I would suggest is that rather than looking for a class that has the exact flavour you're looking for, you simply reinterpret a particular class's flavour to fit a Lovecraftian mode.
For example, I play a barbarian who was blessed by the elemental spirits of his tribe and who's attuned to fire. When he rages, their power flows through him, protecting him and helping him destroy his enemies. It's a simple interpretation of the powers of the class without actually changing them, and I love the end result!
There are several classes you could flavour as Loveraftian without actually changing the base powers. Starsoul sorcerer works, as does Aberrant (think the child of Yog-Sothoth here, or Wilbur Whateley...). There are several witch patrons (insanity or occult) that would suit this theme, and even a few oracle curses. In fact, a straight cleric with appropriate domain picks who worships the Great Old Ones would work perfectly.
Edit: Checked a few cleric domains. Madness and Void would work perfectly with a cleric who channels negative energy as a worshipper of the Great Old Ones.
Hope all goes well for you!
Um.... Sythesist summoner from ultimate combat? Instead of your eidolon (sort of familiar) that comes with the class, you instead merge yourself with your eidolon, taking various features from it. You can then roleplay the creepy factor by adding vestigial (no use) limbs, mouths, and eyes as well as playing the character like he's insane due to the deformities he has. Maybe this isn't exactly what your looking for, but it's something I thought about doing due to a love of lovecraft.
Well, any spellcaster could be tweaked to that IMO.
The origin of tomes from which the Magus or Wizard gain their powers can be very Lovecraftian and with correct spells there are weird things and fearsome things appearing or your body's changing, strange energies dancing and so on.
Alchemist would do better as a class inspired more by stories like the Reanimator (well, there's an archetype for that even), although a psychonaut could find things that are pretty weird too.
Cleric of the old ones and an Oracle can be also easily twisted to the Lovecraftian purposes, as can be the druid. The Witch is also gaining the spells via familiar from some power from beyond. Easily an old one as well. Inquisitor would proably be better at huntig you, although a divine killer is also possible.
It'smostly about spell choice IMO, not just the classes. The spells re the "powers" of PFRPG and many classes could have access to what you may want. For fear you'll do good with Necromancy and with Echantment for mind manipulation (illusions are also helpful and can kill via dread - see phantasmal killer for example). Evocation can manipulate light, but otherwise probably doesn't bring that much. Conjuration is about actually bringing the horrors there to work for you and transmutation changes you (tentacles needed anyone?). You'll probably want to look to first three at first.
Now toward the archetypes (I'll only name those that would deal with dark tapestry and could be tweaked to striker role IMO).
Cleric that would tread the path of more destructive spells, rather than trying to fill the role of leader with healing spells and buffs or controller with summons - see also variant channeling (Ultimate Magic) - Fear, Nightmares, Madness or Rulership (negative energy), Darkness, Knowledge, Madness or Travel domains and Daemon or Fate subdomains (Advanced Player Guide). An ideal harbinger of the old powers return to the world. Inquisitor can also inspire here.
Oracle has Heavens, Dark Tapestry and Time mysteries, again you proably want to avoid leader role.
Sorcerer has Aberrant, Dreamspun, Protean and Starsoul bloodlines and Void-Touched and Warped variant bloodlines.
Withch has quite a few hexes that can be used and Insanity or Time Patron themes.
Thank you all for the help.
I've spent a little more time looking through the books and at the Pathfinder wiki, with the aid of your posts, and now I'm sort of stuck between a couple classes I want to play, haha.
Looking back on it now, I think I was being a little nit-picky, ignoring some good class options because they didn't fit what I was looking for perfectly. I'd also somehow missed the Void-Touched variant bloodline for the sorcerer, which is a terrible thing to have done, because it is an amazing bloodline.
With all of your help and suggestions, I've basically brought my options down to a Cleric of the Void, a Sorcerer with the Void-Touched Bloodline, or a Dark Tapestry Oracle, although we don't have the Ultimate Magic book for the rules on some of those, so the Wiki has been instrumental on helping with my research.
At this point, I think it all just comes down to reading and deciding which would be the most fun to play in this game. Again, thank you all so much for your help, it is truly appreciated.
Sincerely,
- Hethra
Advanced Player Guide, Ultimate Magic and Ultimate Combat are all freely available at PRD (at least the crunch parts). No need to search too much :-)