Blood, Souls, Free Will, and how they all relate to eachother.
Ok. This is gonna be a lot, and probably wildly incorrect, but who gaf. Theory time.
Spoilers below for Ultrakill lore
Blood: In Ultrakill, Blood is easily the most important resource in the universe. It gives life to anything it circulates through. Not just life, but Free Will as well.
Most people use our understanding(however hypothetical) of souls, to interpret how they work in Ultrakill, but I dont think we should.
Why? Machines. We know for a fact that machines do not have souls. They cannot form into prime souls, nor do they have an afterlife.
And yet, they still have free will. They have thoughts and feelings that go far, far beyond basic self preservation. They feel guilt. They feel fear.
The gutterman in 7-2 is the best possible example of this: Even if killing their 'mother' would end with the machines death... they still do it. They even write a poem about it. They hide the poem after writing it.
This, to me, is concrete proof of one thing: Souls have nothing to do with free will, Blood does. Everything alive has Blood, and everything that has Blood, has a will of its own.
Machines have free will. Demons have free will to an extent(Minotaur + Geryon (and demons formed from human remains, like the leviathan)) and of course, angels and humans have free will.
This explains a lot.
It explains why God could never create life without free will. It explains why even Demons can actually act on their own, without influence from Hell. Because Blood is vital for 'life', and Free Will is inherent to Blood.
As for souls: I dont have as concrete of a theory for their purpose, but my idea is that they're processors. They channel the free will from Blood into an actionable form. Souls are the mind. Memories and actions and personality.
But unlike Blood, souls are not vital to life, and substitutions can be made.
Machines use a combination of human biology and literally processors to replace Souls. Demons are likely similar, albeit more biological.
Angels and humans, though? They both possess souls, as direct creations of God. Humans more blatantly than angels, but Gabriel's soul is mentioned in the act 1 intermission.
The only part of souls that can't be substituted is simple: their persistence after death.
Obviously, when humans die they go to an afterlife, depending in the rules God said when He created Hell.
Angels dont go anywhere, but thats likely because God never 'coded' such a function into their souls. They were never originally subject to the rules of humanity, and thus would not go to an afterlife upon death. (Lucifer is technically an exception, but even then, they were sent down physically. They didnt die and go to Hell that way.)
But just because that aspect of their souls differ, it doesnt mean they(human and angelic souls) dont share that persistence.
Prime Souls are formed when something with a soul dies, and its will is so great that it allows them to maintain a physical form without a body. They are walking souls.
And yet they still have Blood. Even without a body, they still. Have. BLOOD. They still have free will, thoughts and feelings and memories.
And if angels also have souls(they do, its been stated) then what is stopping a particularly persistent Angel from returning after death?
An Angel that has been suffering under Hell for centuries.
A person that, despite everything, still resists. Because if they didnt, their tormentor would have gotten bored if them long before V1 arrived.
Yes. Im looping back to Lucifer Prime again!
