Genesistale (undertale AU)

A beautiful day outside

The next day came extremely fast, without warning, me and Taye were both up and I was subjected to several lectures about killing people and monsters by Toriel... I walked outside the ruins where I found Taye, a dummy, and bones littered everywhere. Most of them were sticking out from the ground, Taye was using these bones and throwing them at the dummy without even touching them... It has to be the skeletal arm. Gaster could do the same thing. He looked so into it, I almost felt bad as I called to him. "Hey Taye! Its been too long since we last sparred."
"It's been 3 days." He responded
"'1 day is too long Taye.'" I quoted dad from a long time ago.
"Ha. Ha ha... We really can't go back can we?..."
"Not for now. Neither of us have Determination trait souls, I have to ask you. Can you keep a grudge?"
"It's never good to..."
"It's not good to let a race of murderers exist either. Think Taye, they didn't Spare anyone. Not our parents, not our friends, NO ONE IS ALIVE. They even came after US. They are ruthless, we have to return the favor. We need to train, get better, fight better, If we don't, they may very well come after everyone here in the underground."
"..."
"If you feel that way." Toriel interrupted, I never heard her come out. " Then what is it you intend to do?"
Justice! I'll bring justice to you all!
"... For now, train up these new skills and power."  Just as I finished my sentence, a bone rose up from the ground below me, I barely jumped out of the way, the next couple hours I spent dodging bones from taye to enhance my dodging, and his magical prowess, and then we switched, this him dodging my fire, and when he got tired and went back inside, I tried contacting the angel who helped me during the fight with Gaster, then with the NMO agent... No dice... There was nothing...  Then, frustrated, I moved on to swordplay, keeping up my routine. When I finished, I walked back inside the house. "Heya." Said a voice behind me. I jumped away, startled. "Nice reaction time." Said the shorter skeleton from Gaster's house. "You got past my dad, but he was going way too easy. Sorry, kid, but if you can kill without remorse like that." He teleported outside."Then I have to ask you. Do you want to have a bad time?"
"..."
"It's a beautiful day outside, birds are singing, flowers are blooming. On days like this, kids like you... Should be BURNING IN HELL."
His first attack was a floating skull head, at first I thought it was going to bite me, but my all my battle senses that were imbued in me since I was a child burned with the urge to move out of it's sight, but I stayed put. The skull fired a massive blue beam and hurt a lot. My health was low, but I stayed my ground.

If you are going to survive, you will need to fight back!

That would prove his point, if I can endure his punishment, he might stop.

You're throwing your life to mere chance?!

If that is what it takes. I can't beat him, just by looking at that first attack I can tell I stand no chance where I am right now.

...

His next attack was an army of bones rushing in from the air. Several hit me, one pierced my right arm, another got my left leg, several scratched me on each arm and leg, and one pierced me in the chest, I was lucky it wasn't any of my vitals. He raised an eyebrow, and then sent a ton of very tall blue bones. I moved back and forth, taking the damage from his attack, I barely stood after it was over.
"*sigh* c'mon kid, you're making me feel bad about this, fight back. I know it has to hurt." He said.
All the damage took it's toll. I spat out blood.
"I-I refuse *cough* t-to fight."
"So I have to ask you, did the man you killed plead for mercy?"
"H-he never had, time to."
"One more question, why? Why kill him?"
"That m-man w-was a murderer, he was t-the one who k-killed our Mother, and f-father. He a-also killed many m-monsters in the ruins." His face turned from angry to soft to afraid all in one. "Oh god, kid, I'm sorry. I can't heal.
He can't, I can.
The angel took over and started healing my body. It started with he chest wound and worked it's way down to the minor injuries.
"Thank's Ahn."
"Who's Ahn? And what the hell was that!"