User:GetYourFix/Blog:Ghosts: Mettaton Explained

Hi there! This blog post is my first attempt at a theory post - if there is any way that I can improve, please let me know! If you would like clarification of the canon that I worked with, feel free to post on my message wall.

Theory, in Sum:
Mettaton becomes completely corporeal on the Genocide Route, which is why he does not attack the protagonist. However, the implications of a ghost becoming corporeal are speculative.

I will post relevant canon about the ghosts so that we're on the same page before going into the theory.

Napstablook


Napstablook is a fully incorporeal ghost that the protagonist initially encounters in the Ruins. He is unaffected by physical attacks and lowers his HP because he doesn't want to be rude. Being fully incorporeal, he is one of a handful of characters that can enter and leave the Ruins at will; other characters include the spiders and Flowey. If the protagonist hangs out with Napstablook, he may phase through the right wall of the house. If the protagonist visits his snail farm, Napstablook tells them that his cousins used to work with him before they left to find corporeal forms.

Neutral/Pacifist Route
Mad Dummy is ghost that possesses a dummy in Waterfall in an attempt to become corporeal. On a Neutral Route or True Pacifist Route, the protagonist has a battle encounter with Mad Dummy. Regardless of what the protagonist did to the dummy in the Ruins, Mad Dummy is enraged and explains that that the protagonist scared his cousin out of his Ruins dummy corporeal form.

During his battle, the protagonist can "damage" him with the magic dummy missiles that spawn. After a set number of turns, Mad Dummy announces that "YOU CAN'T HURT ME AND I CAN'T HURT YOU! YOU'LL BE STUCK FIGHTING ME... Forever. Forever! FOREVER!!!!"

Genocide Route
Instead of a battle encounter, Mad Dummy becomes fully corporeal. He is so happy to finally be one with his physical body that he spares the protagonist. If the protagonist chooses to kill him, the "Glad Dummy" will turn to dust and leaves no physical body behind.

Neutral/Pacifist Route
Mettaton is a ghost friend of Alphys who wishes to have a fully corporeal form. In his normal box form, Mettaton is invulnerable to attack, but once he transforms into either his NEO or EX form, he appears to take damage. However, check text states that "his weak point is his heart-shaped core, which indicates that it is not his SOUL. Regardless of whether the protagonist spares or kills Mettaton EX, a physical body remains after the fight. If killed, his box form is shown broken and tipped over. If spared, his Mettaton EX body is shown; he has simply run out of batteries.

Genocide Route
Mettaton transforms into Mettaton NEO in an attempt to stop the protagonist from progressing. He finds it "ghastly" that the protagonist is going to kill monsters and humanity, as he won't have an audience to watch him perform. In this form, he does not attack, regardless of what the protagonist does. The only way to end the encounter is by killing him. Afterwords, no physical body remains.