The Japanese fandom already made the full key lore analysis of paradox chapter 1 last year. So, I`ll gonna translate some of the key lores here.(Sorry about my bad English.)
1.What is the 'right history'?
It strongly seems like ‘the history created only by the inhabitants of that world’. As we can know from Morrigan`s quote that "Even in a right history, Sara had the possibility to become a succubus and suck every people of Sabasa to death", the history of the original trilogy is not the only true history. Once the factors from other world interfere, the deviation grows larger like a butterfly phenomenon. That`s what Lilith sisters and White rabbit trying to fix.
It seems like a Tartarus is just a way to Hades. The only way to other world is a warp portal.
3.About the spreads of Chaos(=Nothingness)
-If a world is derailded from the ‘right history’ by a contradiction event, the chaos grew larger -If the ‘right history’ is truly ‘the history created only by the inhabitants of that world’, to be derailed from the right history, there must be some interference from other world. This can mean that the interference from other world itself is a contradiction event.
-Even if a individual from other world kill the one who are derailed from the right history, it does not increase the chaos. So, it`s not a contradiction event. It seems like, since that person were involved with the contradiction events, thus their presence itself is become a contradiction event. Even Luka is no exception.
-Through actions corresponding to the 2&3 type level contact, the chaos increases. These two actions are the contradiction events.
-The Chaos may had been started at whole worlds in the same time, yet not every world`s spreading speed of chaos are same. While the world through 3rd Tartarus was completely devoured by Chaos, ‘our’ Luka`s world is still in one piece, and the timeline of the world of ruined Iliasville was at 40 years after the great disaster.
-The spread of Chaos can be slowed artificially(anti-Chaos field)
-When the world started to be devoured by Chaos, apoptosis phenomenon facilitates, randomly deleting the organisms.
5.People&factors from each worlds
-Paradox world(Main): Luka, Sonya, Loli Alice, Loli Ilias, Alice 15th, Marcellus, Lazarus, Merlin
-Original trilogy world(?): Ilias(evaluation), Black Alice, Nero&Neris
-World where the angels eradicated monsters: Loli Promestein, Zion, Gnosis
-Ancient(?) world: Lilith sisters -Brynhildr`s world: Hilde
-Collapsed world: La Croix`s note, Radio
-Hades: White Rabbit, Reaper
6.(n)type level contact
-1st type level contact: When you tried to infiltrate to other world/Many apoptosis creatures say this when you are not in other world.
-2nd type level contact: When you interfered to other world/Infiltrating to other world or contacting with the individuals from other world. The one who were heard to done this are Luka`s party, La Croix, and Ilias(evaluation). It is almost certain that Ilias in the evaluation is from some other world.
-3rd type level contact: When you significantly interfered to other world/Action that affects a lot of people significantly. Interfering indirectly(like mind controling) or killing the one who are derailed from the right history is not corresponding to the 3rd type level contact.
(2)What is the ‘level(断界)’?
-It can be interpreted as ‘level = right history’.
Gnosis(when you are with Alice):
“Luka and the monster lord(Alice)`s current level exfoliation is 26%- Though it`s larger than the average, it does not lead to definitive stage. If I execute everyone here, it will be correspond to the 3rd type level contact- The progress rate of Chaos will be 125%, erosion range will be increased to 67%- And one of them is a child of Marcellus. In this world, around that man, the greater the deviation of the space and time. ......Too much risk. You cannot be executed, since you are in accordance with the history until now.”
-So ‘26% of level exfoliation’ means that ‘we are still in accordance with the right history’.
-Percentage of level exfoliation = Degree of being derailed from right history
-(n)type level contact = Classification of the contact method to the right history
There`s a lot of more analysis on each key characters and major factors, but it`s too many to translate for now. Maybe I can translate that part later.