(Little backstory)
Long ago, there lived two creatures that ruled over the earth: HUMANS and MONSTERS.
The humans noticed that all monsters had some type of magic.
They wanted this power too so they started fusing monster souls with human souls, Though this process was dangerous for the monster soul being fused.
Therefore monsters and the forced hybrids fled to the safety of a hole inside of a mountain, the humans that fused the souls heard that doing this was illegal unless it was natural, so to hide the creations they made they sealed the monsters and hybrids underground.
No human has been to the mountain until a curious child named Frisk climbs the mountain and trips falling on a bed of white daisies...this is where our story begins.
If your wondering what the symbol is for those of you who haven't visited the undertale fandom for a while its called The Delta Rune.
Its the one on toriel's robe. I'll put an image below.
Underlimt is my au. Underlimit chara is mine.
Undertale and chara belong to the amazing Toby fox.
(I wrote way too much but I love explaining my au's so-)