A deck builder was just an example of something not based on reaction skill.
But I also think a deck builder has a lot of potential since the game seems to want to differentiate between a combat and "slut" approach to solving problems.
I can imagine seeing getting access to "lewd" cards based on stuff like corruption level and having been defeated and defiled, while combat cards can be obtained through successful combat with bosses and such.
And then quests could potentially reward you with cards based on lewdness, combat, or utility, based on whatever quest it is and factors like corruption level.
Then you'd also have a lot of option for "hybrid" builds that work great for various characterization based on how you've progressed, such as the classic "strict female knight, but reluctantly lewd" and so on and so forth.
That's just throwing various loose ideas out there, though.
I feel like it's easier to apply the philosophy of deck building to regular turn-based combat than to actually make a deck builder. Like most of the deck builders I've played on this site end up either being mediocre as hell or only have one viable playstyle.
I feel like the most important thing when designing a deck builder is how each card synergize with other cards. You don't want them so powerful that every build relies on it, but you also don't want them to be so niche or situational that it's safer/more practical to go for alternatives. But even if the cards themselves make sense, the ability to repeat fights and farm cards/other resources would also throw off the game's balance. It doesn't solve the issue of powercreep the dev is trying to rectify. On top of that, the enemy AI/moveset has to reasonably account for these different playstyles in such a way that you can't just cheese every fight using the same exact strat. And that's not considering that it's very hard to get a novel experience by mimicking the styles that already exist, but it's even harder coming up with something entirely new. If you build it like Slay the Spire, people will just compare it to Slay the Spire, which is a high fucking standard.
I mentioned beat em ups as a possible alternative because they tend to be very flexible. You can have maps be pretty much straight lines like
ErisDysnomia or platformers like
Succubus Affection.
Of course it also has its own drawbacks and challenges, like adapting the sprites and artstyle for that format and getting the hitboxes/responsiveness to button presses to actually work in a sensible way, but I would think that it's more sensible than coming up with like 50+ different cards, figure out how to program them to work, and then figuring out how to keep your player engaged for the entirety of the game. Like I recently played
Is It Wrong to Repay the Debt in a Dungeon?, and it looks like it has decent production value, but I couldn't make it to the end due to how repetitive everything felt.