WMG / Deltatraveler

The game will alternate between Undertale and other worlds

At certain points of the game, the trio will find mysterious grey doors in each world and enter their "Dark Worlds," entering a mysterious subplot. Eventually, they'll return to the Underground and resume regular Undertale gameplay.

• Mostly jossed. Most of the worlds are either other games or Undertale AUs. You will return to vanilla Undertale for short interventions, but that's about it.

Flowey doesn't really die if you kill him at the end

He seemed a bit too eager to allow himself to be killed earlier on, even though you can clearly save over his death. Maybe you only kill an extension of him.

• Jossed. In Hard Mode, it's stated that you killed him. However, he will remember previous playthroughs when you reset a save file, but doesn't express this until The Stinger.

The Greater-Scope Villain is the one behind the transportation to Undertale

After all, those doors weren't originally there in Undertale either...

• Confirmed by Hard Mode, Gaster is the one facilitating this experiment.

Possible worlds Kris, Susie, and Noelle may visit

• EarthBound (Confirmed)
• Repainted World (Deconfirmed)
• Homestuck (Deconfirmed)
• Ribbit (Deconfirmed)
• Mario & Luigi (Confirmed)

Killing the dummy with magic will change Mad Dummy's dialogue

Maybe they'll say something like: "Not only did you destroy their home... YOU KILLED THEM. Bastard. Bastard! BASTARD!" Then Susie would be like: "..."

• Unlikely, since it doesn't appear you'll be returning to Undertale.

Each section will have their main bosses changed

Like how Flowey is fought instead of Toriel, you'll be forced to fight a different monster in each area, having stronger stats due to you having more party members.

• Most likely Jossed, as future sections don't take place in base Undertale, the setting instead reserved for short intermissions.

Kris will force a Non-Standard Game Over to prevent you from killing everyone they care about

Like if you ended up finding Noelle's Undertale counterpart and you tried to provoke a fight. ESPECIALLY when Kris has their world's Noelle with them.

• Confirmed, there's a couple especially cruel choices you can make that results in Kris (or Susie) cutting your fun short.

Kris won’t have to fight Asgore at all

In Undertale Asgore had no choice but to kill Frisk if he wanted to break the barrier, as that was the only way to take their soul. But Kris has been shown to be able to remove their SOUL and survive for at the very least a short period of time without it. Once they learn about the barrier and why Asgore needs their SOUL, they’ll probably take the easy route and give it to him.

• An alternate outcome is that Asgore will refuse to fight Kris due to learning that they live in an Alternate Universe where they lived happily with monsters on the surface and reminding him of Chara.

Possible Guest-Star Party Members

With Paula being Section 2's Guest-Star Party Member, teaming up with other heroes from other worlds is a big possibility. Assumptions here are based on confirmed worlds:

• Frisk
  • Jossed for Undertale Frisk, though GG!Underfell Frisk still isn’t out of the question.
    • Jossed for GG!Underfell Frisk as well, as they do not appear in Section 3 in either route.
• Mario and/or Luigi
• Navi
• Underfell (RynoGG) Flowey
  • Jossed for GG!Underfell Flowey, as Section 3 has no Guest-Star Party Member.
• TS!Underswap Papyrus
• TS!Underswap Chara
  • Confirmed according to Word of God.

Hard Mode's Obliteration Route will have a fight against Toriel

After all, Frisk doesn't have an alternate universe counterpart of Toriel as their mom, so why would they feel the need to fight against the SOUL's control?

• Technically jossed, while you do fight her in both routes, you never actually get to kill her.

Alternatively, attempting to attack Toriel in Hard Mode Obliteration Route will make Kris force you fight Frisk.

After all, Kris revolted against you on normal mode obliteration route. Why wouldn't they do it here?

• Jossed.

The LOSTCORE will be the setting of the final section

I mean, it’s painfully obvious that’s gonna be the case, I’m just putting this here as a formality.

• Confirmed according to Word of God.

Obliteration Route Bosses for future areas

Given that Section 2’s Obliteration Route boss was completely separate from the normal route’s boss, here’s a few ideas as to who I think the bosses will be.

• Hell’s Forest:
  • Sans
  • Frisk and Flowey
    • Technically confirmed and jossed? Sans is the boss of Section 3 regardless of what route you're on.
• Shining Savior:
  • Link
• Mirror, Mirror?:
  • Sans and Papyrus
  • Temmie
  • Chara
• Inside Job:
  • Mario and Luigi
    • The fight will likely have branching paths depending on who you kill first. Killing Mario will send Luigi over the Despair Event Horizon, his attacks slowy growing easier and easier until he either plain gives up or runs away out of fear and grief, or somehow finishes the job for you. Killing Luigi first, however, will push Mario to his Rage Breaking Point, with his attacks becoming faster and hitting harder, whilst a remix of Revolution plays.
  • Bowser
    • Unlikely, given that the chapter is set within his own body.
• Gears and Gaffes:
  • Mickey and Co.
  • The Protagonist
• The Dark:
  • Dess
  • Susie and/or Noelle
  • Kris
  • The Delta Warriors as a whole
  • Sans

Unique gameplay mechanics of certain worlds

It's been hinted that Inside Job will feature gameplay identical to the original game, so here's a few ideas on how gameplay may differ:

• Shining Savior:
  • Real time combat instead of turn-based encounters.
• Inside Job:
  • Instead of bullet board, each party member can jump or use their weapon to avoid attacks.
  • Ability to jump in the overworld.
    • Both have been confirmed. In addition, ACTing will function like Bro Moves.

Alphys will be the one to send the heroes to LOSTCORE

Whether by accident or in hopes of getting help from the original Royal Scientist.

Section 3's Obliteration Route will have a boss where you have to prevent the enemy from sparing you

Especially since the main theme of Underfell is sparing malicious monsters, except this time, the malicious monsters are you.

• Jossed.

Candidates for the Inverted Fate guest star

Word of God confirms that an Inverted Fate character will be featured. Here are a few ideas on who it could be:

• Papyrus (Confirmed; Papyrus appears in the post-section 3 interlude.)
• Spamton
• Lilac

Frisk will participate in the post section 3 minigame

With the amount of time that passed between falling through the first door in Snowdin and traveling through not one, but two worlds, by the time you return to Undertale's Snowdin, Frisk will have caught up to the point where you return and join the minigame.

• Jossed; Frisk doesn't appear due to the interlude taking place before they enter Snowdin.

Inside Job's Obliteration Route will at least partially involve wreaking havoc on Bowser's internals.

Thus leaving him doomed to die a slow and painful death, likely without knowing why if Starlow and the Bros are dispatched before they can tell him what's going on.

The final section will have all of the universes involved combine together into one dark world.

Depending on the route you take, this could end in different ways:

• Pacifist: You return the universes to normal and get a happy ending.
• Neutral: How happy this ending is depends on your actions, but the universes remain merged together.
• Obliteration: You end all of the universes combined together, killing everyone. This could also involve Flowey gaining some sort of Omega form or something similar, seeing as he seems to urge you to continue the route at the end of section 3.

Playing off the above WMG, LOSTCORE will be an All the Worlds Are a Stage final dungeon.

Parts of the section will cycle through all the locales and different gameplay styles encountered in previous sections, with combinations of enemies all from different sections as well. May or may not end with a Final-Exam Boss in a similar style.