Frisk isn't changed much, they are 9th fallen human of this AU.
Chara is still the first human who fell underground. Doe to experiments, they became a goat monster (later they became Flower/Butter the Buttercup)
Kon is second fallen human and Chara's older brother. He comitted genocide and killed Undyne and Asgore.
Toriel is a lost soul and has amnesia. She is still a caretaker of Ruins.
This page is WIP. It will be updated later.