UnderPlus

UnderPlus is an AU sequel to the original Undertale created by Quantis1. The AU tells the story of a genocidal Frisk that lost all their determination when they tried to absorb Sans' soul. the soul rejected the fusion with Frisk's soul, and their separation caused the timeline to entirely reset until the arriving of the monsters in the Underground. This event is known as «The Rupture». Dozens of timelines later, Frisk wakes up in an Underground modified by Sans, with stronger monsters, and minds changed.

A good example of modified fate is Flowey. he'll be telling Sans each one of Frisk's moves and won't hesitate to block your path multiple times. The reason is because now that Sans is the one able to reset, he remembers Flowey's abilities and made a deal with him. he helps Sans in his attempt to kill Frisk once and for all, and once this will be done, the skeleton will let him absorb their soul.

Underplus has a non-cannon sequel named Underplus +, also made by Quantis1. But this page won't refer to it.

### Frisk (and Chara?)

Before the Rupture, they were stuck in a loop of genocide routes. Their knowledge of Sans’s fight allowed them to kill him earlier than supposed. When they saw that his soul wasn't breaking, they decided to absorb it, and from this, the Rupture happened. They're waking up from a long «nap» while their determination was regenerating. Now, they are curious about what Sans can do, but New Underground also means new opportunities and endings...

### Flowey

Since Sans is the most determined being in the Underground until Frisk's awakening, he’s never been able to reset. However, he does have memories from the past timelines (the one controlled by Sans), and is afraid of that power. That’s why Sans offered him to work together in exchange of Frisk's soul once they'll be dead once and for all. As in the original game, when Frisk quickly turns around, they'll see Flowey go back in the ground, meaning he's spying them.

### Toriel

Toriel is more unsure about if she should trust you (the Player/Frisk) than the original one due to Sans telling her that you're a dangerous person. She will submit you to tests during your travel through the Ruins. She won't call you “my child” but “human”. You can see that she regrets having left Asgore due to photographies of them and their children. She wears jewelry and a flower crown, and if you do a genocide, she will talk about her “mistake”, and that it's time for her to assume her role, and protect others like she always should have. However, in a “Pacifist” route, she will act as the original Toriel towards Asgore.

### Sans/KAR-Sans

Sans has brain-washed and changed the fates of everyone, he doesn't care about the consequences since he is persuaded that once he'll have your soul, he will be able to make everything go back to normal. He pushed Papyrus to make harder puzzles, have told the royal guards that you’re here and he is DETERMINED to give you a warm welcome. He is much stronger and won't hesitate to kill you the moment he sees you. It will take much more than one timeline to befriend him, but it's not impossible. More about him will soon come...

### Papyrus

The captain-in-second of the royal guard is one of a kind. Although he will listen to Sans and be aggressive to you, if you show no bad intents, he will attach to you and be your only way to avoid Sans' fury. He has a group of fan named the Paps gang, that will encourage him when you’ll battle. If you go on a date with him, he will tell you, how he saw Sans become more and more worried over the years, and that you might just be the person who could make him happy again. His spaghettis are delicious.

### Monster Kid

Fervent member of the Paps gang, if you spare Papyrus, he will accompany you through the Waterfalls and will be the one protecting you from being attacked. However, if you kill Papyrus, he will only appear on the bridge where he usually falls and battle you. He can be killed in that fight.

### Undyne

“My only mistake” says Sans about her. She growled with a rage against humanity, but when she killed the Kindness Human, she was perturbed not seeing him even try to fight back. Now she just stays in Waterfall, haunted by doubt and regrets. You'll see her multiple times, but she’ll only notice you when entering the Piano Room. She'll say that she hoped you wouldn't get this far before spawning spears, and launching the fight against her. If you spare her, she'll stop the fight, saying she can't do this, and will let you pass. In a genocide route, however, she'll be waiting you at the exit of Waterfalls. A fight similar to Undyne the Undying will initiate, with no possibility of running away.

### Temmies

This happy race will welcome you open arms, they are a little community that believes the humans doesn't deserve to die. While you're in the Temmie Village, you'll be safe from Royal Guards. In Genocide Route, if you enter their village, you'll have to fight, **Temmie, The Hero Of Legends** (Easter Egg fight).

### Mettaton

Due to Sans not knowing much about him, he hasn't really changed. When he’ll see that you can’t enter in Alphys' lab, he'll send you a message about the secret password for Alphys to open you. In a Genocide route, you won't one shot it, and will have to deal with his NEO form.

### Alphys

Undyne will tell you about her that she only opens her lab to Mettaton and Undyne, but that she thinks it's better to leave her alone for the moment. Apparently, she once told to everyone that she had found strange notebooks about multiple things, especially a substance that could heal any hurt monster. However, she stopped showing herself sometimes after her first experiments. However, when going to MTT Resort, you'll find her talking to Sans about “the abominations” she created, and that she still needs his help to find a cure, implying that they are secretly working together to try to heal the amalgamates. Even though Sans knows well it's impossible, meaning he's doing this for another reason... If you talk to Papyrus about Undyne and Alphys' conditions, he'll decide you both need to set up a date to make them reconcile.