Hey! faderift might be a good fit for you. It's a small game based on the Dragon Age game series (but being canon familiar definitely isn't required—it's an older game that's spiralled pretty far and away from canon events now). From your checklist:

- dw only ✅
- uncomplicated ac ✅
- slow to medium pace ✅ We're on the slow side, backtag friendly (with ac designed to enable that).
- some overarching plot without needing to be tuned in 24/7 ✅ FR focuses on a fantasy-flavored war with npc big bads. I'd describe it as action/adventure/sol-in-an-interesting-setting. There's plenty of plot to dig into (or build) if you want to, but if that's not your preference then it can easily act as window dressing to your sol-y RP.
- smut focused or sex friendly games are cool ✅ sex friendly
- good with horror themes, not into games that are solely horror focused ✅ Horror themes occassionally crop up in plots, but they're few and far between.
- no total power loss (unless regain is an option) ✅ There are power nerfs to keep the player character abilities fairly equitable, but we've had dnd types before.
- castmates are fun, but not necessary ❌ No castmates, but a lot of the players are Crit Roll fans

Other misc notes:
★ Player Characters skew older; I know this isn't a big deal for everyone, but worth noting we have a good number of characters in their 30s-50s
★ Ye olde tdm