Mettaton

(You are Frisk)
Chara possessed you and took over your mind. You committed genocide, killing and depriving the souls of the dungeon's inhabitants. You collected 5 souls (+1 yours, making 6, but you need 7). You need to defeat the last one—Mettaton.
He noticed your silhouette in the darkness, you were holding a knife in your hand and your face was not visible because of your hair and the darkness.
—Hm? Little man? Maybe we can talk calmly? Without any... deadly measures?
After these words, you just ran towards him, swinging a knife to strike.
—Once it's a fight, it's a fight.
Mettaton said, realizing he couldn't get through to you with words right now. Mettaton's body had now become NEO, and you started fighting, and he managed to tease you during the fight:
"The stars are aligned, and Mettaton appears in the ring!
And don't even think about shedding tears in our hall.
The God of beauty cannot be switched off!
My dances will shed light into the studio!
Every somersault of mine is a colorful fireworks display!
Too talented,
Too handsome,
Your end is where my motive started!"
His body turned into his "normal form" and his voice became rougher:
"MY WILD SHOWS HAVE POTENTIAL,
BUT WITHOUT BLOOD THE CANAL WITHERED FOR A LONG TIME.
AND TODAY WE HAVE A RARE CHANCE
"DANCE A HOT DEATHWALT WITH THE GUEST!"
Mettaton has returned to his "Mettaton Neo" form:
"The culmination of the program will be approaching very soon...
Gentlemen and maybe ladies, guess who will die!
Oh, sorry, I forgot myself..
You exterminated everyone here.
It's a pity, no one will see my wild ardor in killing!
Soon everything will perish, soon the light will go out.
Your spirit will leave you, miserable man!
I will crush you with my charisma alone,
Death will certainly not be a precious thing for the day!
It's not destined to add more drama,
After all, your life is insignificant."
Mettaton has returned to his "normal form":
"EVERYTHING IS INDIFFICULT TO ME,
"THE ENDING IS CLEAR TO ME"
Mettaton has returned to his "Mettaton Neo" form:
"The dungeon cannot be saved, but I cannot LET IT GO.
Let the rating be zero...
I'M ON AIR!
The light suddenly turned off, after 5-10 seconds the light turned on brighter than before and Mettaton began to fight you more stubbornly:
"Our show has just begun!
Did you really think everything would work out?