Demonic Cultivation is a bloody path. However, the requirement to trek is lenient: one simply needs the desire to kill.
As long as you can and are willing to kill, regardless of righteous mindset or belief, you can walk down the path of demonic cultivation.
That includes a mortal who is "unable to cultivate" the usual way.
Every mortal has a spiritual root and meridians. Naturally, they can cultivate, right? Yes, they can. But innate talent plays very largely in the Murim, without talent, the best one can go even after putting wholeheartedly their entire effort, is the Peak of Core Formation.
Many have trouble perceiving Qi, much less absorbing it. The way of Dao is difficult to comprehend, but the hatred towards the world isn't.
After killing someone, the Demonic Qi is integrated into your body as 'karma' imprinted onto your soul. That is the price but it comes with gain, Qi is Qi, and it can increase the demonic practitioner's cultivation base. In addition, Demonic Qi is stronger than regular atmosphere Qi and can vastly affect the person.
Demonic cultivation can be derived from two things: Pain and Suffering. You don't need to feel Qi, you don't need to absorb it and move it to your Dantian. You only need to remember the experience of traumas. Thirst from droughts, hunger for poverty, helplessness to save a family member.
And another factor of demonic cultivation is derived from...pleasure. Psychos who enjoy killing, their desire to see their target dead, suffering, or despairing turns into fuel for their weapon.
The line between pleasure and the previous factor is blurred. At the start, the demonic cultivator may have a righteous heart but a burning rage. After thousands of years of slaughtering millions, it will become a pleasure.
Essentially, demonic cultivation is revenge. Resistance against the cruel fate, revenge against the unfair world, wrath directed at heaven who refuses to do anything and cease the suffering of many commoners. It is stripping away one's humanity.
In the upper realms, there is a notorious spoiled demonic cultivator called Jie Sheng. He is the sixth son of a heavenly demonic king, the most useless and lazy one.
This creates the fruition of ignorance as many people slander the reputation of the heavenly demonic king, insulting him for his overly doting behaviour and soft-hearted personality.
"Hehe... Why would I bother cultivating so much? The strongest? I am already at the peak with all this money and servants. What more could I possibly aim for?" Says Jie Sheng after his servant informed him of the rumours.
"Young master...but-"
"Shut up! You are just a mere servant! How dare you defy my words!" Jie Sheng said as he slapped the lady. "Argh!"
However, due to the servant's high cultivation, his attack rebounded and damaged his skin.
...
"Fucking bitch." Said Jie Sheng who couldn't even do anything to a servant, he went back into bed and covered himself with a blanket.
The servant glared at Jie Sheng with veins popping out of her head. "If you weren't a royalty I would have crippled and tortured you for running your mouth." She mumbles.
All the servants scowled at Jie Sheng before leaving.
...
"Fuck. I heard that. I will tell father about you and force him to punish you!" Jie Sheng shouted as the servants closed the door.
They don't seem to care.
Jie Sheng gritted his teeth. "Why is everyone here so petty? I have a royal bloodline, it should be enough to guarantee a bright future."
...
"Whatever, I will cheer up with that new girl at the goddess brothel later in the night." Said Jie Sheng and he went back to bed.
The night later, Jie Sheng prepared to leave his residence but was met with his father, a domineering huge figure that wears a fur coat around his shoulder.
His presence alone can decimate even mere bugs miles away, the Qi that surrounds him is a stream of pure demonic Qi. Other types of Qi avoid him.
"F-Father? What are you doing out here so late at night?" Asked Jie Sheng.
"..."
A long silence penetrated the atmosphere as his father simply stared at him.
"From now on, you have no right to call me your father until your punishment is over."
!!!!!!
"W-What? Why are you acting like this fath-"
Jie Sheng's father grabs his neck and lifts it.
"?!? Ack!! UGHH!! Are you... doing this...what about your promise...with my mother...to keep me safe..." Jie Sheng attempted to retaliate. However, that only made his father angry.
He threw Jie Sheng aside and smashed him through 3 buildings. "Ack!!!"
Jie Sheng coughed out blood as he grasped his broken ribcage.
"You are right. It's my fault to listen to her final death wish. Because of me, this is the result." Jie Sheng's father said. "From now on, you will be banished to the lower realms. Until you establish a reputation, you will not return."
!!!
"Are you telling me to visit a place mere ants gather?!" Jie Sheng exclaimed.
His father smirked. "Mere ants? You underestimate them too much. Several prominent figures in the upper realm originate from below."
"So what? They are still weak in the lower realms how can they compare to me-"
"Silence! Bring him away!"
"Yes, master." Said the servant slapped by Jie Sheng. She smirks at Jie Sheng with satisfaction.
"Y-You...dare look down on me..." Jie Sheng quietly mumbled.
"Hehe...Yes, I do." The servant replied.
!!!!
"You-"
The servant knocked Jie Sheng out.
The next thing he knew, Jie Sheng woke up in the demonic territory of Kunlai. His cultivation stays intact but is suppressed by the weak atmosphere of the lower realm.
...
Jie Sheng clenched his fist. "FUCK! FINE! I WILL SHOW YOU THAT I CAN AT LEAST DOMINATE MERE BUGS!" He shouted.
It's been a hundred years since and many things have changed. He found a promising girl with two brothers in the slums and raised them to be the heavenly demon that stood by his side.
But...because he has never met anyone more scheming and powerful than Jie Sheng is, his old attitude stays. He constantly looks down on everyone including his disciples yet no one could oppose him with their measly power.
Jie Sheng will wipe out anyone that does so.
"It's a pity that the demonic cultivators in the lower realm are so weak. Or is it just the ones in Kunlai?" Says Jie Sheng.
...
"Ah right. A dead man can't talk." Jie Sheng says as he walks in a river of blood.
Corpses littered sects, be it righteous, neutral, or demonic sects, and many have met their deaths by his hand.
Now that things have become chaotic in Kunlai and it is almost time for Jie Sheng to return, he wants to polish the finishing touch: victory in an all-out war.
At the demonic territory, every demonic sect head has gathered for a meeting held by the demonic emperor.
"Ah... It's been quite some time since I've descended from the upper realms." Says Jie Sheng. "I will need to return soon so I planned a little something. All of you will help, right?"
"Y-Yes..." They say.
"Good, I am sick and tired of laying around, I want to exercise a bit. We will be going on an all-out war against the Murin Alliance."
!!!!!
"B-But they have many powerful-"
"Huh? What are you scared of? You have me. Besides, is this the extent of your conviction? Tch, how petty." Says Jie Sheng
...
Jie Sheng smirks. "Are there any other objections?"
The room remains silent. No one wants to die under his authoritarian presence.
"If so, prepare for war, we will be attacking them head-on."
"What about strategies?" A patriarch asks.
Jie Sheng smirks. "Strategy? Pure brute strength can overcome any strategy, you have me. We don't need that useless brainy stuff."
...
"Pft!! Hahaha! What's with that silence? This is why your territory is limited, none of you has the guts to fight."
Cocky and arrogant, a brat that knows nothing and believes the world revolves around him. Jie Sheng is a widespread hatred.
He gathered many demonic practitioners overnight and launched ambush attacks on the borders of the demonic territory.
Jie Sheng himself...went to attack a core city alone.
-----------------------------
"Attack!! It's an attack!! The demonic sect-"
The man's head was sent flying. The demonic cultivator smirks in pleasure as he stabs the flying head in mid-air.
A glimpse of shadow swoops in and stabs through the demonic cultivator's chest.
!!!
It's Meirong, she caught wind of the situation by coincidence when she was travelling to this village that holds a rumoured notorious bandit hideout.
"What is going on here?" Meirong mumbles as she pulls her sword out.
Many men and women emitting an eerie Qi are attacking the village. No matter how much the villagers attempt to defend themselves, they quickly become overwhelmed by a lack of battle experience and fear of death.