Lost Souls

The Lost Souls are a group of enemies that you exclusively fight during the Asriel Dreemurr boss fight on a True Pacifist Route. It is intended to serve as a kind of 'boss rush' where one has to fight all the major characters in a similar fashion to their corresponding bosses. It is impossible to attack or kill a Lost Soul as they have high defense.

Attacks

 * Undyne:
 * The Lost Soul throws arrows at the player from all sides in Green Mode and the player must shield theirself from incoming spears.
 * Alphys:
 * Small rectangular Mettatons glide down on umbrellas and which toss hearts embroidered with the letter M as they reach the bottom of the screen.
 * Bombs marked with a plus sign moving downwards, which explode into lasers of a similar formation when shot with the yellow soul.
 * Papyrus and Sans:
 * The Lost Soul attacks the player with a series of bones scrolling across the bullet box, which can be dodged by jumping. As usual, the blue colored bones are used far less often.
 * Toriel and Asgore:
 * The Lost Soul moves their hands along the sides of the screen and leave behind large fireballs that move towards the player's soul after a moment. Stay out of the hands' way and wait for the fireballs to begin moving before getting out of their way as they home in on the spot your soul was when they begin moving.
 * Partial circles of fireballs gradually spiral in from around the bullet box. Find the gaps in each ring and move through them in sequence.

Strategy

 * In order to 'defeat' a lost soul, one must ACT to them three times until their memories flood back.
 * For lost souls that come in pairs, you only need to do ACT three times towards one of the lost souls and seeing how nice you were, the other soul's memories will flood back in.

Undyne

 * All humans will die! [Neutral]
 * You're our real enemy. [Neutral]
 * Mercy is for the weak. [Spare]
 * Well, some humans are OK, I guess! [After ACTing 3 times]

Alphys

 * You hate me, don't you..? [Neutral]
 * I've got to keep lying... [Neutral]
 * All I do is hurt people. [Neutral]
 * No, that's not true! My friends like me! And I like you, too! [After ACTing 3 times]

Papyrus

 * I MUST CAPTURE A HUMAN! [Neutral]
 * THEN EVERYONE WILL. [Neutral]
 * ... [Neutral]
 * NO! WAIT!! YOU'RE MY FRIEND! I COULD NEVER CAPTURE YOU!!  [After ACTing 3 times]

Sans

 * just give up. i did. [Neutral]
 * why even try? [Neutral]
 * you'll never 'em again. [Neutral]
 * >nah, i'm rootin for ya, kid. [After ACTing 3 times]

Toriel

 * This is for your own good. [Neutral]
 * No one will leave again. [Neutral]
 * ... [Neutral]
 * Your fate is up to you now! [After ACTing 3 times]

Asgore

 * Forgive me for this. [Neutral]
 * This is my duty. [Neutral]
 * ... [Neutral]
 * You are our future! [After ACTing 3 times]

Flavor Text

 * The Lost Soul(s) appeared. [Encounter]
 * The Lost Soul(s) stand(s) there. [Neutral]
 * Suddenly, the/its/her/his memories are flooding back! [After ACTing 3 times]

Undyne

 * You asked the Lost Soul to teach you how to cook. She doesn't know why, but she kind of wants to teach you how... [Recipe]
 * You tapped the Lost Soul lightly. Something about the way you fight is familiar to her... [Fake hit]
 * You gave the Lost Soul a big smile, like you remember she likes to do. For some reason, she sort of wants to smile back... [Smile]
 * You clashed against the Lost Soul with all of your might. She feels your fighting spirit... It's familiar somehow. [Clash]

Alphys

 * You tell the Lost Soul that you'll continue to support her. Something about the way you said that is familiar to her. [Encourage]
 * You call the Lost Soul on the phone... She starts to sweat. She doesn't know why, but this all seems very familiar... [Call]
 * You ask the Lost Soul for help on a quiz question. She barely holds back from giving you the answer... [Quiz]
 * You ask the Lost Soul what her favorite cartoon is. She can barely hold back from giving you an enormous answer... [Nerd Out]

Papyrus

 * You told the Lost Soul a bad pun about skeletons. He seems to hate it... But the other Lost Soul seems to like it. [Joke]
 * You asked the Lost Soul for help with a puzzle. He doesn't know why, but he really wants to help you. [Puzzle]
 * You asked the Lost Soul to cook something for you. The Lost Soul is trying to hide its joy... [Recipe]
 * You insulted the Lost Soul. Somehow, it seems flattered by this. [Insult]
 * Seeing how nicely you treated its brother, the other Lost Soul remembers, too! [After ACTing 3 times]

Sans

 * You asked the Lost Soul to take a break from fighting with you... It seems like it wants to. [Take Break]
 * You told the Lost Soul a bad pun about skeletons. He seems to love it... But the other Lost Soul seems to hate it. [Joke]
 * You tell the Lost Soul you think jumble is tougher than crosswords. It seems to have some dim recollection of this fact... [Crosswords]
 * You told the Lost Soul you'd think about what you'd done. It seems like it's trying to remember... [Judgment]

Toriel

 * You tell the Lost Soul that you have to go if you're going to free everyone. Something is stirring within her... [Talk]
 * You refuse to fight the Lost Soul. Something about this is so familiar to her... [Mercy]
 * You tell the Lost Soul you prefer (Cinnamon/Butterscotch) instead of (Cinnamon/Butterscotch). Somehow, she faintly recalls hearing this before... [Preference; depends on choice at the beginning of the game.]
 * You hug the Lost Soul and tell her that you're going to see her again. Something about this is so familiar to her... [Hug]
 * Seeing how nice you are, the female Lost Soul's memories returned, too! [After ACTing 3 times]

Asgore

 * You tell the Lost Soul that you're going to save everyone. Something stirs deep within him. [Talk]
 * You stare deep into the eyes of the Lost Soul. He remembers the gaze of humans past... [Stare]
 * You hug the Lost Soul. It seems like his aggression is slowly melting away. [Hug]
 * You tell the Lost Soul that you won't hurt him, no matter what. Something about this is so familiar to him... [Mercy]
 * Seeing her remember you, the male Lost Soul tried hard to remember you, too! [After ACTing 3 times]

Trivia

 * Attempting to attack Undyne's soul will cause "MISS" to show up more than usual.