So here's an idea.
One of the core concepts of the Xianxia mythos is that everything improves.
A person that is higher up the chain will be generally stronger, smarter, more spiritually developed and more longevity.
There are specific exceptional growths in various areas, but they'll only have a significant penalty if they have some horrible injury or flawed cultivation.
What if that wasn't intrinsically part of the system?
Imagine this scenario.
- Some person starts practicing martial arts, driving his body far beyond human limits
- This makes him strong and fast, but it also puts a huge strain on his body, prematurely aging him and reducing his expected lifespan to ~40 years old
- Then, once he reaches some threshold, he changes his cultivation and reinforces his body
- This improves his regeneration, de-ages him, and increases his lifespan to ~200 years, but takes away most of his exceptional strength and speed
- Then his develops his spiritual power, gaining magical abilities
- But the power is unstable and will tear him apart in 100 years
- He consolidates his spiritual power, reducing what he can output, but extending his lifespan to 400 years
- Repeat for mental abilities, gaining and losing memory and thinking power at the cost of mental stability
- Then go back to physical, leveraging the extra mental and spiritual gains to reach even greater heights
You could also imagine people experimenting with skipping cultivating parts, or trying to cultivate multiple parts, with limited success.
There are a several advantages of a partial cultivation system.
It makes the world much more heterogeneous since any given person might be cultivating different parts.
It would tie the cultivators into social groups as they require allies to protect them on the consolidation stage.
It would place another consideration on how quickly you can advance beyond just resources, you also have to consider the timing and context.
A person might be a genius at one type of cultivation and overtaken in the next cycle.
The MC would have very different solutions to problems as their abilities change wildly from one cycle to the next.
The MC would have all sorts of character development as they become smarter/dumber/more enlightened/less enlightened, which is distinct from many Xianxia novels where they declare that the MC has suddenly become a genius, even as he keeps on doing the same dumb shit.
Well, from a practical "writing xianxia" standpoint, the fact that your character capabilities keep changing dramatically might make it more challenging to write, and the fact that he keeps abandoning previous heights of power, and actually depending on others, is going to be problematic from a "appealing to the pure power fantasy" standpoint. Once you get past the Doylist side, though....
It's interesting, certainly. I think *particularly* interesting here is how far you go on each stage. basically, each stage is a matter of first converting stability and lifespan into power, and then converting power into stability and lifespan, and making a profit overall (though you do spend time doing it, which means that you're always spending that lifespan too). One of the questions, then, is how far you go, and how far you come back, and how efficient it is, and how long it takes. All of that is going to be a matter of cultivation art, talent, drugs taken, and so forth.
For example, in the Three Deadly Demons school, the practitioner is expected to pick one area in which to excel (depending on their talents). Let's say you get a guy who'e specializing in physicality. He cranks his physical training all the way up, taking himself dangerously close to the lifespan edge (possibly using some secret forbidden techniques to even let him walk *over* the edge), before cultivating back in the other direction enough to not tear himself apart, and give himself enough lifespan for the next step, still leaving him fairly swole. Then he cultivates spiritual power, and again rockets up as far as his lifespan will let him go, but this time he cultivates it back basically down to nothing, reaping significant lifespan benefits. Finally, he does the same in mental - up crazy-far, then back down to almost nothing. Now you have a guy with a lot of mental stability, a lot of spiritual stability, plenty of lifespan, and major physical prowess (though not so much regen). He does this through a few more cycles, and winds up as a physical powerhouse that no standard cultivator can match. Of course, on the mental or spiritual battlefields he's very weak in some ways, but that's why they go around in matched teams of three.
On the flip side, the Wise Elder school takes a much slower path to power, with cultivation techniques that take longer, but are much more efficient at converting both to and from Power in all three realms, and they pretty much convert all the way back down every time. It is a point of pride for them how little out-of-phase Power they have at any one time - as far as they are concerned, Power still left in the system is wasted, and is Lifespan that you can't convert out the next cycle. Their cultivation style takes a significant period of time, but they wind up extraordinarily durable in all three areas, and their peak power is pretty impressive too. Essentially, they drain every scrap of improvement they can out of every cycle. On the other hand, they pretty much don't leave the sect - the thing that keeps them all safe is that at any given time, there's guaranteed to be a few sect elders who are in the Power side of the cycle, to defend the rest. From that sect, even the thousand-year-old fifth-cycle Ancient Master, with a 30,000 year expected lifespan, can still lose in a fistfight to some young sprout, if he's not in the right point in his cultivation.
