What I was thinking about was an MC who lives in world of swords and magic, with a twist. There exists a level system in this world for the inhabitants to get stronger whether it be an animal, human, demon, or even a tree they all have the ability to level up. You gain this ability as soon as you are born and everything in the world has that ability, just the way they level up is different for each race. Trees and Grasses and the like can level by absorbing the energy in the air until they gain a consciousness and can begin communicating and can kill stuff to gain exp faster. Humans, Demons, and Animals can get small amounts of exp through training by absorbing the energy in the air, when they master a technique they would get bonus exp for mastering it, and when they kill things.
The MC was born into this world as a normal kid so he has the same emotions a normal kid would have: curiosity, naivety, and the like. There isn't anything special about him other than the fact he is more gifted in perception than others his age. He can read people's emotions and can tell if they are lying or not when they talk to him. He notices this when his parents say they love him, even though he could see hidden bitterness deep in their eyes. After he notices that, he notices lots of other things happening, too. He noticed that some of the older people in the family avoid him and don't talk to him, he notices that he doesn't have any people his age to play with, like all the other kids do, he realized that his family didn't care about him.
After the realization hit, he took it upon himself to go to the family's library and read every book there pertaining to survival, training, living by himself, and the geography and customs of the world so he doesn't get lost or confused at what to do. He reads every book in the library until he stumbles across a book that explains the reason his family doesn't care about him, he can't level up. He can't level up doing anything, when he absorbs the energy in the air he doesn't gain exp, he doesn't know about what happens when you kill something or master a technique though, as he is still a little kid. He finds the reason they don't love him is simply cause he can't gain exp.
Learning this he decides to run away from home, as there is nothing keeping him at home, his parents don't love him, none of his family cares about him and just think he is a waste of space and resources. He leaves a note, that his family probably won't even bother to seriously read and heads off into the woods cause it's safer than in the city, where people can kidnap him and sell him as a slave, kill him, and could get bullied by his ex-family members.
When he gets to the woods, he thrives. He gets experience in hunting and gathering, gains survival instincts, makes a shelter, and establishes his own territory in the woods. He learns there that when he kills something he still absorbs the dead animal's energy but doesn't gain exp, same for mastering a technique, because he has already mastered separating the animal into pieces and gained the "Dissection Mastery" skill, "Trapping Mastery" skill, and "Long Range Mastery" skill from hunting and felt energy gather into his body but didn't gain any exp.
He continued this life until he turned 8, by then he had already forgotten about human contact and had already grown more animalistic. He now only wore animal skin clothes and doesn't make any noises as he has no need to communicate and just focuses on hunting, his previous short, neat blonde hair had grown to the middle of his his back and flared out to look like a lion's mane, his muscles became developed for fighting and survival and became scarred with bite marks and cuts covering a lot of his body, and his teeth became sharper and more carnivorous.
One day, while he was cooking the food he hunted that day, he saw an old man walking towards him, laughing crazily with tears falling down his cheeks. The old man said that he would take the boy who had forgotten his name, as there was no need for one, under his tutelage and teach him to become strong in ways he couldn't imagine. The old man explained that he has a body constitution that doesn't allow for leveling up as it defies the order of the heavens. He says that the boy had the same body he had except to a higher degree. The body they had could absorb the energy of the heavens and allow them to temper their bodies and minds with it, leading them to increase their strength directly, without the need for status points or needless slaughter of living beings, even though it could increase their prowess much quicker when they did kill, and once they get strong enough their lifespan increases, too, the same way it does with normal people.
However, because their bodies are so heaven defying whenever they advance a stage, they have to experience a tribulation. This is worth it however because this tribulation purifies their energy, tempers their body, and you can absorb the leftover energy to increase your soul strength. Their body's aren't limited by attribute or whether they can master magic or fighter abilities because as they can directly absorb the energy of the heavens (Qi) that makes up all the elements, they can use any element they want. If they fail the tribulations, however, they get crippled or even die with their soul destroyed.
Even after hearing all this, the boy still kneeled and paid his respects to the old man and accepted him as master. This signaled the start of the old man and animal like boy's journey to become stronger using Qi in a world of leveling up.