[SPOILER] Plot Discussion Thread *Spoiler Alert*

[Kein]

Interesting theory. Then, if those blue objects aren't hearts or Orbs (even fragments of a single one), what are they?

I don't know, seems like hearts indeed, according to level data. Either way I just provided 3 arguments why these aren't Orbs against not a single fact or argument that specified in that "wiki" (lel).

The temple map does contain a reference to orb_room.DAE and orb.ent (which uses orb.dae). Only one orb.ent is placed in the scene. I haven't actually seen them when playing, but they are in the map file.
There's also models for the orb in 6 stages of being shattered, but those aren't referenced in any of the maps or scripts. (Part of the unused alternate endings)

Yes, the map contains many references to the orb, because it was in original story and ending. Seems like they forgot to remove it, just like some voiceover files with unused monologues.

As for 6 pieces of orb - these entitles migrated from DD.

The two glowing objects at the end ARE Orbs. There was originally one Orb and it fractured, which also fractured the personality of Mandus. I initially thought that they were the children's hearts as well, but it makes a lot of sense that they are the orbs powering the machine.

My only question is why does the machine remove your heart? Do you do this intentionally, to free yourself and "cleanse" your misdeeds? Or does the machine (engineer/dark self) kill you?

Chemical X is just Vitae/Brennenburg serum with added touches. The machine itself was using this (and other things) to create the hybrids using pigs and humans as test subjects (as well as the creatures from decent)

see

Are we sure there aren't orbs in the temple at the end? Several people thought these were the twin's hearts but take a closer look at those pics (full size recommended if you want to see something):

There are two objects in the map called "child_heart_1" and "child_heart_2", those would be the glowing things.