Well, I mentioned taking a few inspirations from dark souls...
In that game, you can beef up your strength to swing around a great sword one-handed, or use the weapons of your enemies- some of which are about 20 feet tall...
You could consider that high-powered.. Until you see what you are up against.
I am considering adjusting it, maybe to 8 or something... But the story I'm considering (expedition to a lost city in the forest) isn't going to be a walk in the park either.
Some of the perils that make this world dangerous or existentially threatening include ;
Trace amounts of blight in water everywhere, not enough to provoke a Fort save
Blight in the soil, poisoning fruit and crops. The sun is also dim, so that doesn't help.
Varying levels of blight in animals, mutating them and making a lot of their meat poisonous
Breaking blight wood releases some spores, burning it creates a poisonous fog.
So, right there.. Finding food and staying warm.
Then there's undead. People occasionally come back. As ghosts or ghouls or zombies, ect.
Demons roam aimlessly killing and raping and eating.
Devils have settled in old ruins, laying claim to the surrounding areas
Probably something like 1 damage a minute.
More generally, the gradual loss of fertility and loss of sanity.
So.. Imagine your walking from one town to the other and a Balrog is on the road.