welcome to Techtale where monster have made powerful technology that can give you powers, but they needed something to be this powerful but they didn't know what it was. above the undergrounds monsters and humans lived togheter they were happy, years later the humans feared he monster and they were scared they would take control of them, after on tragic incident happen between the monsters and humans, war happened since the monsters weapons were weak they lost sent to the undergrounds. The monsters were trapped in the undergrounds, when the first human came down her, with quick reactions monsters killed the human, soon realizing the thing to make there weapon powerful was human souls.
TobyFox-for undertale