So I am an idiot forgetting there were comments to the update post. I haven't used reddit in a while so there's that. I was utterly shocked to find out details about the end game item, and as I scrolled through the comments here, people generally had the same idea. But I have more to add and this is my theory on the item.
Caliborn's end game item is a JUJU and is a complex one at that. From an earlier point in the story we could see that John had gained retcon powers by phasing through it; enabling him to visit any point in time and space beyond the conventional rules of time travel dictated by theories. We can see in this update that the JuJu can trap 4 souls for eternity, and it contains the souls of John, Rose, Dave, and Jade. This would explain all if not, a lot of the powers Retcon John has.
What if the JuJu, after trapping 4 souls, utilized the power of those 4 souls? If this were true then Jade and Dave would give the JuJu Space and Time powers respectively. Rose would give some control over using spacetime to travel to any point thereof using only one timeline and one universe. Rose's classpect is the seer of light blatantly meaning she can see fortune; so if we play with this it could mean "I see what I want". And in turn gives the user the control to travel to any point they want to when they see it for example, the password updates that Terezi tells john to go to using the 'Redscarf of Key Words'. Finally John's classpect deals with inherited freedom (Heir of Breath) which could be "I can be anywhere" in a play on words, and would give the user to go to any place and any time they like across all of reality.
This would explain John's ability to zap into caliborn's shitastic homostuck story. It's a story made by a character with limited rules on the physics and reality of its realm. Yet John just waltz's on in without a clue. It would also explain how the JuJu becomes intangible itself. John's Retcon powers enable him to go out of bounds with his current reality. Maybe the same can be true in retrospect for the JuJu only every power it is utilizing is in reverse which would make it exist outside of reality.
But I want to take this a step further. The JuJu traps four souls for eternity and utilizes those souls as a weapon. Imagine if anyone else besides John, Rose, Dave, and Jade were trapped inside the JuJu. Let's use the other 4 kids as an example.
Jane : Maid of Life ~ Active Healing/Creation class of bending reality to her whim. Literally maid to play with the heartstrings of reality.
Roxy : Rogue of Void ~ Changes and moves things about to obfuscate them. Or in roxy's case steals things from the nothingness i.e. Creates objects.
Dirk : Prince of Heart ~ Destroyer of souls. Prince destroys their aspect and Heart deals with who people are. So i am right in saying Dirk literally can kill a person's souls. Killing their second life in the after life in the sense of double death while still being a live, AND then killed by dirk.
Jake : Page of Hope ~ The way that I understand it the classpect is an amplified powerhouse for other classpects. Essentially providing more power to other classpects.
Jake would initially give the user of the JuJu incredible monumental power, but currently powers of nothingness and yet of everything. With Jake's classpect we could say here that it would give the power equal to that of the Lord/Muse class in which the user has control over the entirety of their aspect. With 3 other aspects in play this is going to turn out huge. Dirk gives the power to destroy a person's soul, and with Jake in play the user can manipulate people's souls instead. Roxy gives the power to steal and destroy objects/information, instead the user can both destory objects/information and be given ungodly information, information that was never to be spoken nor revealed. And finally with Jane's powers added to the JuJu and amplified with Jake's the user would have the ability to manipulate ALL OF REALITY AND LIFE AS WE KNOW IT. Scary isn't it? This version of the JuJu would probably be a ticking time bomb waiting for someone to come along and destroy all of reality and life.
Caliborn calling his JuJu as a weapon against him is a way to see how monumentally stupid he is. And if he ever used his JuJu for himself then everything that homestuck was would be doomed from the very start. Maybe that is the real reason why lord english is out in the void instead of searching for his sister, he would be searching for his JuJu.
Now that I think about it, this could reveal some possible future events that are yet to happen. But I've rambled on long enough and want to hear your thoughts. Please.