The future world- monsters have been trapped under Mt. Ebott for ages. With you as their ambassador, they have finally risen to the surface.

Based off of an indie game by Toby Fox- it came out in 2015. Um, genre...
FAnTaSy!

Long ago, there were two races- humans and monsters.

For a time, the two races lived in peace- but then war broke out. The humans forced the few remaining monsters underground with a magic spell, sealing them there forever.

One day, many years later, a human child fell into the underground after running away from home.

So much happened then- you killed them all, reset, and became their friends, over and over, wiping their memories every time. But in the end, the murderous thing controlling you was destroyed... or so you thought.

With that new freedom, you freed the monsters and lived with them in peace. You lived with two, specifically- the last two skeletons. Papyrus and Sans. More on them later.

This story is the aftermath.

Normal- with the exception of soul manipulation.

Magic systems are unique to each monster! Humans do not have magic, but different colored souls. Human souls are in the shape of hearts, while monster souls are inverted, or upside-down, hearts. They all have limitations, however.

Monster magic, for example, cannot conjure things out of nowhere. They can manipulate objects that are already there, but no magic can just, poof.

Soul types have to do with the nature of the human in question- yours is red. There are eight types total, and some humans are mixes of multiple types. Types can change over time, but are prone to change back without a lot of attention. The different types have different colors. Some monsters have magic that involves being able to manipulate souls in different ways. I will list those, as well:

Red- Determination. Your soul type- never, ever giving up. Red cannot be used as an attack/magic type, but with enough determination, you alone can reset your world at will.

Orange- Bravery. Categorized by recklessness and courage. Some monsters can use orange attacks in battle. The only way to dodge these attacks is to run straight at them. Kinda self-explanatory.

Yellow- Justice. Categorized by souls with a passion for everything to be fair. If monsters have justice in their souls (Sans) they can Judge other souls. Judging tells the Judge the soul's color, type, and level of violence (L.O.VE.), which states how much blood is on your hands. Yellow attacks are difficult to explain- in short, even after they hit you, they slowly take down more damage.

Green- Kindness. Categorized by souls who want to give to others, no matter what they get in return. Monsters cannot manifest green ATTACKS, but if a green "attack" hits you, it restores health. For this reason, green magic is categorized as healing magic. Only very powerful monsters have it, with the exception of Vegetoids, common monsters in the Underground, often used to provide food.

Cyan- Patience. Categorized by souls who are- you guessed it- patient with everyone they meet. The only way to avoid cyan attacks are to stay still and let them pass through you.

Blue- Integrity. Categorized by souls who are honest (sometimes to a fault). They mix well with Yellow souls, and wholeheartedly approve giving a wrong-doer their dues. Boss monsters, skeletons, specifically, can turn your soul blue. If you are under the effects of blue magic, you will be weighed down heavily to the ground, making it very difficult to move. Blue magic can also move souls at will- up, down, and horizontally- along with other objects.

Purple- similar to Red souls in that Purple souls never, ever want to give in. But Purple can be manifested as an attack. With the effects of Purple magic, you are only able to move between horizontal pathways. Simple as that.

Finally, White- Compassion. All monster souls are white, because at their core, all monsters are made up of compassion.

However, as I mentioned, these can all change. One of the ways a soul can change colors is if there are cracks in their soul. Since cracks only occur though really painful trauma, when they heal over, it's often through a color that isn't your normal color. If there are enough cracks and heal-overs, your soul might slowly graft over that color.

Actual mechanics are difficult- most human technology is old, and falls down into the underground some way or another, so by the time it's hit the bottom, it's in need of repair. However, magical technology is INCREDIBLY advanced. ex: the soul extractors, soul capsules, the Core, or even just Mettaton.