You've stopped caring whether or not anybody sees you.
Yes, you can hear the monsters you pass by whispering about how you're the human that sacrificed your SOUL, the one to save all monsters. You can feel them staring at you in awe and pity. It makes you grit your teeth and walk faster. If they knew...if they knew how many times you've killed them in cold blood...how many times you've stepped over their dust as you've felt your LV raise, your power growing...
You can look at each face and remember the look of fear and horror as you ended their life. Some fought. Some ran. Some just stood there in shock. Their reaction hadn't mattered to you, at first. You'd hunt them down if you had to. It was just a matter of completing a goal. Of marking off a checklist of requirements that just happened to involve murder.
But you remember when you started to enjoy it.
At first you'd blamed Chara. You'd told yourself that you were just sensing their feelings, their sadistic delight in the sensation of dust at your fingertips. You give a dry laugh as you recall trying to convince yourself that you weren't 'evil', because you weren't enjoying it. You remember trying to excuse yourself, because you were exempt from consequences. What was so bad about killing somebody if in the blink of an eye you could bring them back?
You didn't know the answer until you finally wanted them to come back and stay 'back'. You thought you could just go back to the surface and start again - you'd satisfied your curiosity and your hidden desire to kill. You'd smiled into the sunrise as you stood on the surface, walking off hand in hand with mom as you all headed off to start your new life.
And then you faced your consequences.
It'd been only mildly annoying at first. You went back and tried again, saving the Underground, breaking the barrier, bringing your family to the surface...
Only to wake up and see yourself kneeling in their dust.
It took several times for you to start to get scared.
You'd started pleading with Chara to stop hurting them - you'd told them they'd killed enough, that it was time for both of you to move on and let everyone be happy now. They just laughed at you. You could spend days and nights begging with them, trying to barter something, anything, that you thought might convince them to spare your family and friends.
You'd just feel their sick smile on your face as they swung out with their knife and killed again.
But why had it taken you so long to feel guilt again?
You step off of the Riverperson's boat onto the snow, eyes tired and dead as you trudge into town, ignoring the stares and whispers. Why had it taken you so long to feel anything about killing your friends? Are you really that heartless? Have you really just been seeing them as pieces of a game?
Your gaze flickers to the side as you pass by the shop, watching the bunny behind the counter chat with a customer.
'Please don't hurt my family'
You'd only read the hastily scrawled note a few times. The first time you looked at it, you winced. You felt something stab at your heart, and you had RESET, losing your nerve. The second time you just hesitated, and then crumpled up the note. The third time you read it, you were just...unreactive. It was nothing, at that point, to you.
Everything was. Every life and plea for MERCY was nothing.
"HUMAN?"
Eyes widening, you turn and see Papyrus rushing right for you. His face is etched with concern. You step back, looking left and right for some sort of escape. Instinctively you think about reloading a SAVE before remembering that you can't do that anymore.
"HUMAN! I WAS SO WORRIED ABOUT YOU! YOU WEREN'T THERE FOR BREAKFAST SPAGHETTI! I CHECKED MY PUZZLES TO MAKE SURE YOU HADN'T GOTTEN TRAPPED BUT YOU WEREN'T THERE EITHER!" He reaches out a hand towards you and you step back again, lifting your shoulders. "...HUMAN?"
You keep your gaze emotionless as you watch his shins, unable to lift your eyes to his face. He stares at you a moment before reaching out again, slower.
"THERE IS NO NEED TO BE AFRAID, HUMAN! THE GREAT PAPYRUS HAS NO INTENT ON CAPTURING YOU!"
This time you shove his hand back, gritting your teeth, "N-no-o.." You growl, brow furrowing as you clench your fists.
He gawks, and you can sense passers-by doing the same as they stop to watch the scene play out.
"Do-o-on-n't t-t-to-ou-c-ch.." You grumble.
"...O..O-OKAY! THAT'S FINE! YOU DON'T NEED TO BE GUIDED ANYWAYS, I SUPPOSE! YOU KNOW WHERE MY HOUSE IS AFTER ALL-!"
"N-o-ot-t go-oin-ng." You say stiffly, narrowing your eyes. You feel a dangerous burning pressure building up behind them as your chin quivers. "L..l-le-av-e.."
"HUMAN-?"
'I don't want to be friends.' You finally force yourself to sign, every finger stiff as you do so, 'Leave me alone.'
"...BUT-"
This time when he steps towards you, you shove him back, "NO!"
The look on his face forces you to turn and walk away quickly before he can see you start to cry. When you reach the tree line you start to run, sobbing quietly as you run as far from the town as possible. You don't stop until the pain in your chest acts up again, forcing you to fall to your knees and brace your hands to your sternum, taking in shaky breaths and crying out in pain.
"Golly, Frisk! That was coldof you!"
You close your eyes and grimace as you hear Flowey's voice from in front of you, "Fl-low-w-ey.." You mutter, wincing at another sharp ache and curling over yourself, panting.
"Yep! It's me, best friend! Or, I guess you don't want friends anymore, huh? You've dusted Papyrus hundreds of times but I've never seen you hurt him like that! Who knew you could be so soulless?" He starts cackling, but immediately stops when you start weeping, putting your face in your hands and soaking your palms with tears.
You hadn't wanted to hurt him. You'd just wanted to keep him away from you. Although you know he'll probably come looking for you anyway, or at least send another sentry, because he's worried about you. He cares too much to let unkindness stop him.
"...alright, stop it already, you crybaby!" Flowey snaps at you, sounding uncomfortable, "When has crying ever made it better for you anyway?!"
Taking in a sharp, deep breath through your nose, you suck in your lips and slowly sit back, wiping your sleeve across your eyes and giving a shaky sigh, 'Sorry.' You sign. At least with Flowey being able to remember through RESETS, he can still understand you. He'd been very reluctant about learning ASL, to put it lightly, back on the surface when you'd taken him with you. But he'd gotten fed up with not understanding you and begrudgingly put in the effort to learn.
Of course, these past hundred or so RESETS, it's not like you've really talked with him. So he's probably a little rusty.
At least he recognizes 'sorry'. "Hmph. Well, isn't it hilarious to have you finally say that! But nothing like an apology to make up for dozens and dozens of murders, right?"
'What's being soulless like for you?'
Flowey squints at you, presumably taking the time to work out your message. "...what?"
'I feel a lot of pain...and emptiness. Like I'm missing something important. Is this what you feel?' Your eyebrows furrow in concern as you look at him, 'Have you been in pain this whole time?'
For a good half-minute he's just silent, staring at you before huffing and looking off to the side, "Like I said - you grow numb to it."
'I thought you meant that I would because I'd.' You pause, biting at your lip and swallowing, 'I'd stop feeling everything. You said it only gets worse.'
"For you it will. I mean. I don't know. Not like anybody's ever been stupid enough to give away their SOUL before!"
'Then how do you know about it?'
He gives a dark smirk, "Because I've taken SOULS before, of course!" He says cheerfully, "I've tricked monsters into summoning their SOULS and then taken them away! I wanted to see what would happen."
You shudder, not exactly comfortable with being reminded just how cruel this flower can be, 'And you said they-'
"Lost themselves! Their memories became more and more confused until eventually they were forgetting their own names. They couldn't recognize any family or friends. They forgot how to speak after a while, too! Then they were like stupid, mindless animals." Flowey rolls his eyes, giving a scoff, "It was funny until everybody would start crying about it."
You're tempted to scold him for being so cold about the subject, but wisely decide that you're in no position to be lecturing, 'So the pain stopped?'
"I don't know. How could I? It's not like they would talk to me if I kept them prisoner and if they went home then I couldn't hear or see them because they'd hole themselves away!" Flowey frowns at you, sneering a little, "Does it hurt that much, bestie?"
'Yes.'
"Don't you think you deserve it for everything you've done? For all the pain you've caused your 'friends'?"
'Where's mom?'
Flowey squints at you, looking abruptly confused, "What?"
'Where's mom? Where's my mom?'
"What, Toriel? She's still in the Ruins, stupid. Where else would she b-hey!" Flowey shouts at you as you take off running, gasping in panic as you try to find your way out of the woods.
"M-o-om!" You cry, feeling terrified as you see the darkness setting in. You've changed your mind about leaving. You know you promised her you wouldn't come back, but you don't want to be out here anymore. You're lost and scared and everyone keeps trying to hurt you...
Eventually you stumble out of the woods, your face and arms torn up from branches and brambles scratching at your skin. You recognize the sentry path and run until you see the giant door. You pound your fists on it, "M-m-mo-om!" You sob, bracing your cheek against the cold surface as you cry out for her, "I-I'm s-s-so-or-ry! I-I d-do-on't w-wa-an-n-t to l-le-ea-v-ve! M-M-o-om!"
There's no response.
You sink to your knees, weeping and curling up against the door. The sky starts to gradually get darker, and your crying has tired you out. You slump against the giant barrier, sniffing and shutting your eyes. "I-I-I'm-m s-s-so-or-ry..." You whimper, drawing your knees to your chin and shivering, "I-I'm s-s-so-or-ry.."