I've had an ask for a entirely new Cauldron, forr the new machines. and before I go into that, I'd like to put this disclaimer, this has revisions to the Router, and some of the story as-is. first off, Sylens is dead, straight dead, and he's no longer a AI. the actual AI Loki, which has taken over as APOLLO's knowledge section (anyone who knows the true Loki mythology as according to Norse mythology knows he's also one of the most powerful war gods there are), and is stockpiling information about the Ancients (nearly said old ones there). in addition, the Router act as an extension of Loki, actively seeking out scholars on the old ones, and having their own presence in Meridian, along with Carriers, and other Machines, which have now entered a golden age. they can choose to attack (which they do surprisingly often), with knowledge of doing so will basically invite their doom. or they can choose to be peaceful, and live with the humans.
specifically, the new machines actually have entirely docile versions of themselves, for instance, Snapmaws have taken to complete docility (is that even a word? pretty sure it is, and I might edit it out later), and actually serve as a kind of ferry system, in exchange for being allowed a percentage of resources, to take back to the Cauldrons for refurbishing (I'm checking the spelling of that, and turns out, it's correct).
in addition, there's a entirely new Cauldron I'm adding (or three). and the first one is this: ALPHA. followed quickly by DELTA. ALPHA is the place where the new Large machines reside, such as the Burnraiser (that's your hint I'm adding more). DELTA is the medium machines, such as the Carrier, and Grounder, and Striker. but, the small machines, where do they go? believe it or not, OMICRON, which for those of you googling it instantly, know it's not what it sounds like. I actually have no idea what it sounds like, I literally just smacked the keyboard and cross refferenced (S, spelling?)
OMICRON is one of the weird Cauldrons, having been created as a catalouger, they mark machine sites, and basically do the books for the entire terraforming system. it houses the Router, Darkwalker (yes, you can fight one inside there, but it's not recommended), and various other machines of small size. the Router, while in this Cauldron, is always accompanied by at least one Sawtooth, which will buy time as the Router escapes, letting out a roar that, despite the fact it can't normally, draws in a pair of Longlegs (this part is a cutscene). then, after they're drawn, they all engage, it is recommended to use a Tearblaster, as it can strip them of components easily. and, the Longlegs will most likely be crippled by that, as they feature a lot of exposed components. the Sawtooth is the best thing to target with a few blasts.
main reason for visiting is to gain the overrides for the Router, Darkwalker, and such. more specifically, it offers a surprising amount of datapoints, including a log hinting at a new machine, refered to as "the Walker." if you must know, it will be released in a future post. not saying which.
only disadvantage of visiting is the time it takes, you can easily spend an hour winding through the labrynth, and pathfinding doesn't work while inside.
DELTA is where the monsters dwell, including a literal swarm of Grounders. specifically, they won't attack you, but they will flee if they spot you, meaning you can actually use them as your little guide, because they remain tagged as they head to the Cauldron Core. free guide, eh? also, you can find partially built machines there, including, in the core, a nearly complete Stalker pair, which will awaken after the energy shield decends and repairs them, allowing the player to study them. at this point it will be revealed that they're not stalkers, they're Hunters, the more dangerous kind. specifically, they're a new model called Headhunters, which seek out their killer until they're dead, forever. so, long story short, after killing them you have to deal with them blocking the only way out, and them chasing you for about four months, which, if you let them kill you after exiting the Cauldron it literally does nothing.
main advantage of visiting is it has a high loot yield, with very little cost. though, after the first time, the Headhunters don't attack. there's only two. instead a pair of actual hunters are there, waiting, fully made.
main disadvantage is that the Headhunters are the worst kind of stalkers, and will follow you from their home in the Forbidden West (specifically, just barely inside, guarding the pass through) all the way to the Nora lands, where they will stop short of following you into the Embrace, but they will destroy anyone who exits, savaging even the hardiest hunter. and every now and then, one of them will kill someone on the inside. doesn't that send a shiver up your spine? a pair of immortal, unstoppable killers pinning you to a wall, and then toying with their food?
ALPHA is the strongest Cauldron, as it is guarded by a pair of Thunderjaws, and it doesn't get any easier the whole way through. in the final room, you have to fight a Sparkbringer, a Wyvern looking creature that has all the worst features of a Stormbird, with the extreme durability of the Burnraiser. it classifies as a Medium machine, but is exclusive as the final room guardian for Cauldron ALPHA. in addition, it will rarely come as a pair, and then you're expected to die a good three times before getting it.
main advantage is you get to override the Sparkbringer, which afterwords will appear from time to time. it also will appear at the major Settlement Meeridian, appearing with a rider and the rider offering a quest to Aloy. free ride to a bandit camp, you kill them single handedly. except they've got the ability to override machines, and have the ability to call hostile machines to guard their base. the Burnraiser is docile until you try to override it. then it goes apeshit.
main disadvantage is that you also remove a large amount of trust the Machines had for humans, meaning you get attacked a lot more, and even by some Burnraisers.