[Spoilers] Human Soul + Monster Soul = Angel Soul?

[Pizzarugi]

So I've decided to do a third pacifist run, this time resetting instead of completing the prerequisites. This has given me some time to investigate areas again for more lore I can use towards my hypothesis thread. As it turns out, the Waterfall area is absolutely riddled with backstory and lore that I completely glossed over on my first ever playthrough and never bothered to read again.

Unlike my hypothesis thread, most of what I have to say is speculation based on what little lore is presented as well as events that occur in the game itself.

Index

1. Humans, Monsters and Angels
2. Asriel and Chara/Frisk
3. The Delta Rune
4. TL;DR

1. Humans, Monsters and Angels

It's established quite obviously in the game that monsters and humans are vastly different creatures. Monsters are magical beings with little determination and are driven by love and compassion, making them weak. Humans are physical beings with powerful determination, but are given the choice to do good or bad deeds, making them strong. Unlike humans, monsters are capable of taking a human's everlasting soul, making them incredibly powerful as a result.

So what could happen if you combine a magical soul driven by compassion and empathy with a physical soul of intense determination and free will? According to the signs in Waterfall, this fusion creates a "beast of immeasurable power". Note that they describe the result as a "beast" rather than a monster or human. This could mean the resulting bearer of combined souls has possibly transcended to a state that is difficult to describe.

So my speculation: A fusion of monster and human souls are permanent and results in the creation of something I'd like to call an "angel" soul. A third, unique soul, whose power far exceeds the souls that created it, and is so rare that neither monster or human have any significant data about them.

Simply being very strong from this fusion doesn't seem like enough reason for humans to go to war with monsters, considering monsters are simply too weak to attempt such a thing to begin with. There has to be more to this, something incomprehensibly powerful that would make the humans fear the monsters.

2. Asriel and Chara/Frisk

Asriel/Flowey and Chara/Frisk, what do the two of them have in common? They both lived together for a time until a conspiracy to shatter the barrier ultimately killed them both. Besides backstory, they're also the only ones capable of "saving" and "resetting". On extreme ends of the spectrum (genocide and pacifist), both are capable of erasing entire worlds at will! There is no mention anywhere else that even mere humans are able to perform such a feat, meaning it has to be the result of an angel soul.

So here's some things to consider: As soon as Asriel had taken Chara's soul, they immediately became a single entity, their souls combining to create the angel soul. This also would have an effect on Asriel's body, as monster bodies are manifestations of their souls. That means when Asriel eventually dies from the attacks by the villagers, the dust he spread from his dead body would also be infused with this new essence. Flowey isn't just a flower with Asriel's monster essence mixed with determination, Flowey also has the incredible power from the angel soul itself!

As for Chara, this is a little more complex. Flowey clearly doesn't have a soul, but human souls have immense determination, allowing them to persist forever after death. Asriel's soul would perish momentarily after he died, because of how boss monster souls work. However, since he had taken Chara's soul, this means he can live on forever because of the fusion. Remember how evil Chara mentions after a second genocide run that they're a "demon" who comes when someone calls their name? The reality is that Chara is an "angel" as a result of combining their soul with Asriel's, but believe themself a demon due to their new purpose from reincarnation: The pursuit of power. If you believe my hypothesis, that you are Chara, that same power to return when someone calls your name also applies to you even if you took the pacifist route! This is yet another power provided by an angel soul!

And consider the feats you've performed during your adventure, pacifist or genocide. Six other humans had fallen into the underground before you got involved, each and every one of them fell to Asgore and his plans to break the barrier. None of them are mentioned to share the power you had to control saves and resets, meaning you possessed a power none of them had, something that makes you far greater than a mere human.

3. The Delta Rune

The Delta Rune, as described by the turtle merchant in Waterfall, is ancient and predates written history. It's original meaning has been lost to the ages, and is now being used to describe a modern prophecy, that an angel who has seen the surface shall return and the underground will go empty. Lately, monsters have taken a bleaker outlook, and see the angel as an "angel of death", a harbinger of destruction that will free the monsters from their mortal realm.

If you fight Asgore a second time and spare him without Flowey killing him, he'll also relay the same prophecy, that a soul from the heavens will return to free the monsters.

It's quite possible the angel in the rune is literally an angel, or someone with an angel soul. Who has seen the surface? Both you/Chara/Frisk and Asriel! Since the rune can predict an angel of death or angel of freedom, it also implies that angels have free will to choose a good or evil path.

4. TL;DR

Humans and monsters are opposite of one another across various aspects, each with their own strength and weaknesses. When their souls are combined, their weaknesses are cancelled out and they become a whole new soul that is capable of possessing immeasurable power such as controlling saves and resets, coming back to life when their name is called, and having the strength to wipe out entire timelines. This is an angel soul.

Asriel and Chara/Frisk created one such angel soul, when Chara conspired with Asriel to go to the surface. When Asriel died, his transformed dust (and determination from Alphys' tests) created Flowey, a soulless plant with the power to manipulate time or destroy timelines with enough power. The angel soul reincarnated when someone called Chara's name, creating Chara/Frisk, who also has the power to control time and destroy timelines.

The Delta Rune prophesized that an angel who has seen the surface will return and the underground will go empty. It's safe to assume that the angel could simply mean a human, but it could also be literal, a person with an angel soul who will return from death itself to free the monsters for good or bad. You, as Chara/Frisk, are that angel, for you have seen the surface.

[Pizzarugi]

The hope people will notice my threads and add to the discussion...
It fills me with DETERMINATION.

[Crystalitar]

Very cool. My own theory was that the delta symbol was made because of the fusion of asriel with chara's soul. Hey, toriel wears it on her cloak, maybe this was a certain symbol they had when wearing royalty clothes? So asriel wore it, the symbol got noticed while seeing a beast (angel) that goes to the surface and will come back.

[CyperAleksi]

Well I suppose Chara/Frisk "combination" (possession of Chara?) of some sorts makes most sense given that the other humans didn't seem to have this power, or if they did, it wasn't as strong.

Delta rune can be seen both as angel of death or destruction as you stated basically, given the different routes.