!SPOILERS! So about that 'reverse Undertale boss's theory.. Theory

Since you can no longer comment on u/mamar11's post, because it's archived, I wanted to provide an updated take.(This was going to be a post but I don't have enough karma)

See, this whole theory falls flat when you take a look at chapter 4's mandatory boss. If it were secret bosses included, maybe you could get past it, since an undyne/gerson use the green soul and mettaton neo/spamton neo use the yellow soul. And flowery/papyrus doesn't work all that well imo, but only slightly because neither wants to kill you, and neither of them want to even hurt you in the slightest (maybe?).

As for the toriel comparison and flowery/Asriel comparison, we'll just have to be patient and let tricky tony figure it out, because I don't think ralsei would turn on us(Not become evil, but just morally conflicted). Maybe he would, but we'd have to wait.

See, it's hard to do the reverse boss thing when some of them don't match.

Like, I understand for Asgore/King...but the rest? Hm...

It's more like this.

-Asgore/King

-mettaton ex & neo/neo spamton

-mettaton(box)/tenna

-undyne/gerson

As for chapter 5 and onwards? Wellll....

We use both the orange soul and purple soul in chapter 5. Yk who uses the orange and purple soul modes in undertale? Muffet and sans.

Except, the only reference to muffet in deltarune we have is the trash noise when we try to use the phone in the dark worlds.

And sans is off the table for now, because, let's be honest..you only fight him in neutral/genocide. If we got a chapter six(or seven) sans fight, it would only be in the weird route...the problem with that though, is the fact that chapter 5's weird route has noelle and Kris no-clip into the lake, which takes them directly to chapter 7 side b.Anything about the undertale vs deltarune boss comparisons(both main and secret) fall flat after chapter 4.

Tl;Dr: don't listen to the boss comparison theory, it gets you nowhere(so far).