Underfell doesn't have a strict canon per say. The endings aren't as fleshed out as they should be and there are controversies about the relationships between characters. For this "timeline", let us just have an open mind. Feel free to tell me what doesn't make sense. This was a 3AM story rush, obviously.
-~o~-
It has been a long journey. The two companions just finished exploring Alphys' True Lab, and revelations had surfaced. Flowey, or Asriel as he wants to be called now, is still a flower. He has a plan to free the monsters and show them this world can become "Save and Be Saved. As a bonus, getting the human souls will lead to him having feelings again... for a short moment. THey had finished their long walks over the lower city. The castle awaited.
Asriel :
Almost there, uh ?
It sure took a while.
Ah ah...
It's funny... I don't have
any soul yet, but I feel
nervous anyway...
Do you think King Asgore...
Do you think my father will
believe us ?
That we can live outside ?
That we can live in peace ?
I mean... We're asking a lot.
For every monster to lend
their souls to me...
Doesn't sound safe when I
say it out loud.
Comfort him ? - - - - - Do not
Asriel :
No.
You don't have to choose
anymore, Frisk.
We've been over this.
I can do this. I must do this.
No time for complaints.
... Let's go.
The two of them advance. The pillars on their right are as majestuous as they remembered. Although, in this timeline, it's the first time they stepped here. Frisk advances slowly, embracing the serenity of this place. Asriel keeps his guard up, just in case. The two of them watch the light of the sun piercing the glass on their left, creating beds of shadows on their path.
They go on past one pillar, two pillars. However, before they reach the third, a familiar face appears in the shade of the fourth one. A smiling face full of sharp teeth and harboring a glowing red eye..
Sans :
heya.
you've been busy uh ?
Asriel :
You!
The flowery companion instinctively curves his petals forward and produces his floating projectiles, but for once, he restrains himself.
Asriel :
...
Sans :
... well ? you're not gonna
attack me ?
The lost prince let his pellets vanish and his roots return him to the vase. He was right to be cautious, but showing hostility is not his way, not anymore.
Asriel :
Sorry... Frisk...
I almost forgot about him.
Oh well...
Angrily looks at Sans :
What do you want ?
Still disappointed by our pacifist
approach ?
Sans :
eheheh... you have NO idea
how right you are.
There was something different about the way Sans looked. Last time, or rather the other time, he just laughed at how the two of them couldn't escape being hated and hunted. How they were forced to pick sides and sacrifice people. But maybe, maybe this time, he knows they had followed a righteous path.
did i ever tell you about my
eye ?
it's simple, really. it activates
while i defend myself.
nobody can get close to me
unless i feel like it.
pretty nifty, right ?
a guy like me... all bone...
I'm easy prey around here.
sorta...
so, to keep myself safe,
I have to use all i have.
all the time.
day and night, i keep my
guard up.
that's the world we live in.
or at least the world i USED
to live in.
Asriel :
Great story...
And now you can take a long
break. No need to thank us.
Sans :
sure, bud. live in your fantasy.
i'm being serious here.
if I didn't wanna be hunted,
i'd just hide.
well, i'd take my boss along,
family's family.
but because of your meddling,
this world... is not ready for
the war.
you've infected it. with your
silly words, hugs and kisses.
it's all ruined.
Asriel :
Ruined ? What are you
talking about ?
Who would want a world of
"Kill or Be Killed ?
Sans :
me.
sure, if my boss got offed, i'd
feel bad. but that'd mean he was
weak.
it's how the universe works.
believe me, we've seen this motto
work out pretty well.
who knows ? i'd let myself die if
doing it made a stronger monster.
eheheh...
you know what i mean, right ?
buddy ?
Sans kept his crimson gaze on Frisk, as if he knew something Asriel didn't. He had no idea, and chose to ignore it, for Sans had started moving forward. One step.
but here and now ?
Second step. The skeleton bowed his white head. Then with his third step he let the duo see his face. His eyes were empty, presenting a void hungry for souls, and his smile was creepier than usual.
Sans :
i don't feel like holding back.
A chill ran down both heroes' necks. Even the flower. Thankfully, the mad mystery let his normal face return, though words remained heavy with gloom.
Sans :
if you meet the king,
and reveal WHO YOU ARE.
welp. that'd do the trick, for sure.
family reunion. that's a big sale
on forgiveness.
that'd break him.
you'd convince him to summon
everyone you befriended.
Papyrus. Undyne.
Alphys. Mettaton.
and
what then ?
You'll free us ?
we're letting you put the entire
Underground out in the open,
for friendship ?
...
hell no. i'm not falling for that.
you're just a pair of sadists
trying to play with their feelings.
and then you'll redo it all. just
for a laugh or two.
i mean, 0 EXP ? that's pretty
unrealistic.
Asriel :
We're not trying to trick you.
You want to stay here for
eternity ?
We will make the monsters
happy, free.
Even you must want that!
Sans :
meh... to be honest, I don't
care if you will or won't.
I hate both outcomes.
it may surprise you, but i like
it here. despite the murdery
business.
i let PAPYRUS have his fun.
he's my boss after all.
i let folks hate me.
i'm my brother's bro after all.
it's fine. i can take it.
so long as they come out stronger
and way more ruthless.
survival of the fittest.
the birth of true MONSTERS to
fight the real monsters.
humans.
you may have fooled everyone,
bucko, but not me.
i've seen your kind, time after
time after time. anywhere and
everywhere.
you despise what is different.
you eliminate what disgusts you.
you even destroy yourself.
it's all a big game for you.
so you'd better stop acting like
you're the damn hero.
cause i know who you truly are.
what you really are.
deep down underneath that skin.
...
a skeleton waiting to be pulled out,
painfully.
...
a'right.
enough with the jokes.
enough with the chatter.
you want world peace ?
you want an end ?
you want some fun ?
you'll have to fight me for it!
The bony boy takes a stance and prepares to fight. But what can he do ?
Asriel :
Frisk. I'll assist you.
We can't stop now.
You have to SPARE him.
You have to CONVINCE him.
I believe in you!
Put that tubby skeleton back
in the closet!
Frisk stretches his neck and gets ready. He doesn't know it, but he's in for the performance of his childhood.
To be continued...