Backstories do not affect the main story. They simply give you an insight to the character and there abilities.
(So reading them optional)

Reader Pov.

Screams drowned out the loud crackling of fires as it engulfed everything it touched. My vision blurred from the smoke and tears. The thick smoke caused my eyes to water and my lungs to burn. I walked through the burning village in a daze as people screamed and ran or slept completely still on the ground. I wasn't sure if I was dreaming or not. The cold texture of the earth felt good between my little toes. I took another step and the coldness was replaced with a warm sticky liquid. My little eyes drifted down to see my red reflection staring back up at me. I cocked my head to the side as I studied the red liquid, before finally crouching to stick my finger in it. I twirled it around for a moment, before I rubbed the red texture between my thumb and index finger, fascinated with it. I slowly started to bring my blood covered finger to my mouth, when a pair of strong arms knocked the wind out of me as they picked me up harshly from behind before tucking me underneath their arm as they ran. I glanced up to see my dad frightened and covered in the same red texture.
"Daddy what's this?!"
I asked, in a curious child tone, pointing the blood covered finger up at him. So he could get a better look, but he didn't look or answer. Instead he just kept running.
"Daddy what's this?!"
I demanded even louder, kicking my feet out and stabbing my finger at him once more.
This time he spoke, but it wasn't the answer I was expecting. Instead he let out a soft sigh of agonizing pain, as his legs slowly started to give out. Before coming to a stop all together. He dropped to his knees lingering there a second, allowing me to stand back upright on my own again. His eyes fixated on me and his dry blood crested lips moved, but no sounds escaped his mouth. Before I could ask my question again he tumbled over onto the ground, were he laid motionless. A large pin wheel blade stuck into the center of his back.
A very strange man I had never seen before approached from the shadows. He ignored my presence ripping the blade out of my father back. Sending little red droplets everywhere. He kicked my  dad's dead body over face up. His eyes were still wide open and his mouth still gaped, like a silent scream.
He pulled out a kuni and thrusted it into my dad eye, shifting it around in small circles. After a minute of crud work, he reached inside and retrieved his prize. He held my dad eye out in front of him, admiring his handy work. My dad eye didn't look like a eye anymore, in fact it looked like a beautiful red crystal.
He jammed it into his belt pouch, and quickly retrieved the other one. Tucking it safely inside with the other one. He wiped the sweat from his brow still wielding the kuni, before noticing me for the first time.
"Oh wow, is it my lucky day. Two for the price of one."
He said, his voice ecstatic as he reached towards me like he was going to pick up a newborn baby.
"Come here you little Kemono."
He spoke, as he gently took me into his arms cradling me on his forearm so I was face to face with him. I glanced down at my father bloodied empty eye sockets.
"You might be the last of the Kemono Clan you know that little one. Making you very valuable in the long run."
He stated, bumping his arm upward underneath me, so my attention turned back to him.
"What's this?!"
I asked him, pointing my dry blood covered finger into his face. He gave it a once over before answering .
"That my dear is blood."
I brought my finger to my face studying it again, before asking another curious question.
"What's blood and what's a ke..kemono ?"
This time he just laughed, until tears started to form in the corner of his eyes.
"Your alright kid."
He choked out between laughter, before finally tiring himself out.
"Blood is something that everyone has inside of them and Kemono means beast."
I was in awe by his vastly knowledge and how willing he was to share it with me. I wanted to know more.
"So I'm a beast?"
He chuckled, pretending not to hear my question.
I think I'll call you [f/n].
You might actually end up being more useful to me alive than dead someday little Kemono. "