Heartwind’s religion is nature. Elders are chosen by nature through being good to nature. What about a group that gains strength through torturing nature controling it? The problem is that is so much like the force in star wars. The dark side etc. there is good nature worship and evil nature worship. What gains are made by being good or evil? How does evil nature worshiper actual worship and how does nature reward them or give them what they are wanting? Maybe bring fire to the bent tree bridge and push the fire towards the tree to make it bend. How does evil nature worship change a person or develop a society? How will the 2 groups interact? Do they live peacefully as in harry potter where former death eaters and everyone else live normally? Or do they never mingle at all until some event happens? Stolen sheep or crop or something destructive happens or someone is killed. Maybe a love affair between 2 people like romeo and juliet.
What a bout a military element where young men either follow the way of nature or off the the mechanical militarl machine part of the society.
Nature lovers vs. exploiting man living together in moderate peace.
What are the weapons of heartwind? Be careful not to move too closely to avatar. Sling shots crossbows. Whips, staffs, blow guns?
Hary potter was everyone and those who used to be death eaters. People got along for the most part. There was definitely tension. Should heart wind have some sort of past? Where some chose to go one way and others another? Maybe drug induced strength speed vision intellegence. People who used nature for its spoils and what herbs and flowers they can put together to get them high or for whatever they need.  That could work.
Take this potion and be able to run very fast or throw hard and fast.
Eat this and be able to talk to the animals. Maybe they did this and forced sheep to run fast or fish to come or bushes to hide.
nothing can replace hard work. There is no quick fixes. You must learn and experience to be great. Not take a pill.
Heartwind’s past was turbulent. You have those who are at one with nature and those who exploit nature.
Opposing religious ideas.