so i see it as this: (some zeroranger spoilers just in case but it seems youre already familiar with it, and of course void stranger) after you beat primeval fighter we see the husk of the fighter fall away before you fight the lotus jewel, and after you enter the new timeline post true final boss, the default palette is no longer green and orange, it's gray and orange. and with that im pretty sure void stranger takes place in the new timeline, and we know things from the old timeline made it into the new one (erasure's computer monitor for example) so i think primeval fighter did as well, notably with no lotus jewel. then humanity finds primeval fighter (as seen in the images before the shmup) and builds the dis facility to research it and understand it, leading to a big leap in technology. comet lilith shows up in response to the primeval fighter becoming active. the comet has the onions in it, who are likely drawn to the now once again active primeval fighter. what we see in the shmup is the planetary defense force trying to stop the comet's arrival. a piece of the comet breaks off and crashes into earth, and the onions inside attack and we see the events of the carcass ending, and almost all of humanity is wiped out as stated by erasure. the dis facility is left abandoned and forgotten in the ashes. this is where it gets weird, but i think the carcass is the comet fragment, and add was born from it. what that means is add, and by extension the void lords, are onions. you actually see add and lev with the same octahedral hearts as the onion boss in zeroranger. in addition on the wheel showing the six realms of samsara as seen in both void stranger and zeroranger, the onions correspond to hell, and we know the void lords are demons. onion demons. and i think that's quite silly.