Eight Humans

The Eight Humans are the only humans from the Surface who fell through the barrier on Mount Ebott into the Underground. Among them are the first human, the protagonist, and the six other human SOULs that Asgore has collected.

Each SOUL Mode and colored attack type corresponds to one of the seven humans that fell before the protagonist.

Main Story
Before the events of the game, seven human children fell into the Underground and died through their journey.

Asriel found and befriended the first human. The royal family adopted the human and treated them as a second child. The human became deathly ill by eating buttercups and requested to see the Golden Flowers from their village, but the monsters could not fulfill this request because of the barrier.

After the human died, Asriel absorbed their SOUL, and the human (who also had control of the shared body) carried their own empty body through the barrier to their village. Ultimately, the humans on the surface fatally wounded Asriel thinking he took the human child's life.

He retreated Underground where he collapsed on the flowerbed in New Home. After his death, Asgore declared war on humanity and pledged to kill any human that fell into the Underground. Toriel then left for the Ruins because his actions disgusted her.

Sometime after the first human fell in 201X, six humans climbed Mount Ebott, fell into the Underground, and died. Each of them had their associated items, but it is unknown why they climbed the mountain. Asgore collected each of their SOULs for later use, and he also put their bodies in coffins in the basement of New Home.

The protagonist is the eighth human to fall, and their SOUL is the last needed to break the barrier permanently.

Neutral Route
The coffins holding the bodies of previous fallen humans are found in New Home. The first human's coffin is empty because Toriel took their body with her to the Ruins. Toriel buried them under the flowerbed that the protagonist initially falls on at the beginning of their journey through the Underground.

Near the end of a Neutral Route, Asgore reveals the six human SOULs which Flowey ultimately absorbs to become Photoshop Flowey.

During Photoshop Flowey's fight, the human SOULs rebel against him when the protagonist calls for help. The SOULs aid the protagonist with healing green attacks. Flowey's defense drops every time the protagonist calls to one of the SOULs for help. After the protagonist defeats him, the human SOULs revolt against Flowey, and he loses his powers before he reverts to his earlier flower form.

After the credits, Sans tells the protagonist that the SOULs have disappeared, precluding the plan of breaking the barrier with them.

True Pacifist Route
On a True Pacifist Route, Toriel tells Asgore that he only needed one SOUL to leave the Underground, and that he could have spared the other fallen humans if he had peacefully collected the other six from the Surface.

Flowey absorbs the six human SOULs and most of the monsters' SOULs to transform into Asriel as a child. Shortly after, he becomes the "God of Hyperdeath" and his battle begins.

After the protagonist SAVEs the Lost Souls, he reverts to his childlike form, destroys the barrier, and releases the SOULs.

During the epilogue, the protagonist finds that the coffins in New Home's basement are now open and that the first human's coffin has mummy wrappings in it.

Genocide Route
At the end of a Genocide Route, the fallen human appears in person. It is unknown whether they are speaking to the player or the protagonist. They say that "determination" and a "human SOUL" brought them back from death, and that with guidance they realized the purpose of this reincarnation was power.

The fallen human attacks the screen and the game closes. After launching it again, the fallen human appears after ten minutes and offers to recreate the world in exchange for a human SOUL.

List of human SOULs
During the Photoshop Flowey fight, the SOULs attack the protagonist with their related weapons found throughout the game. When playing the Ball Game, the protagonist may achieve any of seven flag colors, all with a different message and each corresponding to one of the SOUL colors (Red, Light Blue, Orange, Blue, Purple, Green, and Yellow.)

The following is a list of SOUL colors and the details associated with them.