Okay, so even more so than many things I ask, this has zero bearing on the game of this forum, but attempts to ask Google didn't pan out, and I've got a number of knowledgeable 40k fans, here, so I'll give it a shot.

So, if you travel to Terra, and look in the Emperor's dressing room, you might notice the huge, gaping warp rift; what's left of the Emperor's attempt to breach the Eldar Webway. Now, while I want to bother with "why haven't the Eldar done anything, even if NOT to help the Imperium?", or "if the Webway is, for the most part, shielded from the Warp, why did the HUGE warp rift happen, when Magnus the Red did his Avon call", the one I'm going to focus on is "why is this rift so difficult to close?" beyond GW says so, it's grimdark!

There are Necron pylons around the galaxy. I'm not saying they could bring one in, but I sort of am. They train numerous Blanks to serve the Inquisition, and an entire Temple of the Assassinorum is comprised of Untouchables so strong they have the reaching out aura, and might be able to disrupt Daemons with their very presence. Most, or all, of the Custodes certainly aren't psykers, either. Why not just have the Custodes take up all the Null Rods they can find, seconded by a handful of the Culexus' best Operatives, and maybe any Sisters of Silence they have left (jury is still out), move against it, maybe supporting an effort to encapsulate it in whatever makes a null hold work? Is the Emperor too close to it, though the Custodes, and a few Titans, can fight in there, day after day, for ten millennia? Alicia Dominica didn't seem to be harrassed by a titanic fight, when she was brought before the very form of the Emperor, nor did some of His most important Custodes seem to be too bothered leaving Him, to go fetch her. I get the combination of "GW doesn't ever really move along", although the one casualty in Mont'ka REALLY surprised me, and "it takes (in)action to maintain the grimdark", but apart from the company that owns the intellectual property, is there really any mechanical reason this task becomes so hard? Surely, they have ways to deal with some warp incursions, and to keep even the Eye of Terror from growing, so...

So, thoughts? Any good, internal reasons this is still a problem? It might not really take any strain off the Emperor, battling the Ruinous Powers, and all, while in His state (unless he's directing that effort through the hole?), but it would seem a good problem to fix.

Couple of points.

1) The Emperor's exact status right now is a little bit unknown. It's entirely possible that his soul is currently inside of the Warp Rift keeping it closed, and his body is "tethering" a part of his soul to reality so that he can continue to Astronomicon, make new Astropaths, and appear to small children in their nutrient paste breakfasts. Whatever is happening, it is implied to be extremely, extremely tenuous and breaking it for even a moment might shatter it forever. It's working, don't fix it.

2) The Golden Throne is reasonably large by human standards, but probably not larger than say a Titan. It is however much smaller than the last "Warp Rift" to open inside of an overly decadent, ambitious, and hubristic Empire which eventually became that little "Eye of Terror". A few warp rods are not going contain an explosion that could conceivably take out the entirety of Terra. Or it might. But no one is seriously going to test it. The Warp Pylons are also not quelling the Eye of Terror, because the Eye of Terror was formed long after the Necrons were defeated. All the Cadian Gates are doing is allowing for a stable passage in and out of the Eye of Terror. Also the Cadian Gates are breaking down.

3) As for why the Eldar haven't just shown up to help, you should read The Beast Arises series. In non-spoiler terms, the Emperor was building his own conduit into the Webway, so it isn't part of their existing network. Secondly, that conduit is now broken so the Eldar are not going to "open" it from the other side because that'll just cause more than a few problems for them. And they don't show up to help most of the time because no human is seriously going to believe that the Eldar are going to go before the Emperor and not try to kill Him. The Imperium literally relies on the dessicated nigh-corpse of a man sitting immobile for a mind-bogglingly long period of time. The Imperium was warring against the Eldar a lot before the Heresy, so they might be better off now than they were pre-Heresy.

4) Even if building a Null cage would work - are you sure that it won't just overload it? It's still technology, and it could still be used to bring very human Chaos marines through to target the cage and shoot it from the inside. You need complete, absolute, 100% denial of any Warp energy, which means you also can't be passing through it because then it's not completely sealed. In which case as soon as it breaks the entirety of the collected psyche of millions of years of suffering pours through into Terra. Again, not ideal.

Consider, the Sisters of Silence were deployed against the Thousand Sons. This was not a curbstomp battle for the Imperium, they were making progress, but then Magnus showed up and was so powerful he could overpower the "field" that the Sisters were generating, and even if he couldn't target them directly he could suck the air out from around them, compress the air above them to crush them, explode the ground beneath them... being Untouchable did not save them.

I think there are lots of reasons why it couldn't just be fixable, and part of it is that we don't know the exact nature of what happened. Magnus broke something, and the Imperium might never recover. If there's a way forward, it will probably be more difficult than piling some magic rocks in front of a hole and hoping that's fixed it.

There are two big problems with fixing the warp rift. At least it's only accessible after passing through a number of enormous fortified gates, so the general populace neither knows about the problem nor has to deal with it.

First, it was created as a result of catastrophic failure on the part of the Imperial Webway. The Imperial Webway itself was an attempt by the Emperor to backtunnel into the original Webway created by the Old Ones; but not being an Old One himself the Emperor instead had to make do with jury-rigging, slow ritual, and psychic brute force. So now that the Emperor's out of commission beyond propping up the Webway Astronomicon and helping to keep things under control to assist the Custodes, no one (or at least no one who'd be willing to help) has the knowledge or technology to actually repair the damage.

Second, the warp rift is a major salient of the Warp upon realspace. The forces of Chaos know on some level that if they can just break through to Terra on the other side, they can cheat their way into their endgame objective of controlling humanity like playthings after grabbing/corrupting the Imperial leadership and the Emperor. The Custodes know this too, which is why Chaos hasn't broken through yet, but regardless there are a lot of demons on the other side who would like nothing better than to make fashion accessories with your entrails. Any sort of repair team who went out there would have to be heavily defended.

That's not to say that it can't be done, mind you, but rather that it's **** difficult to pull off. The ideal solution would be to find some Old Ones who aren't hostile and to explain the problem to them, but good luck doing so between intolerance of xenos and finding Old Ones who are alive but not hostile. (My RT group managed this last session, but they're working with a less intolerant society and really had to work their way up to finding the Old Ones. Plus the whole tone of that campaign is "the crew gets up to some seriously crazy nonsense, news at 11"; we all understand that it's very much non-standard.)

Couple of points.

1) The Emperor's exact status right now is a little bit unknown. It's entirely possible that his soul is currently inside of the Warp Rift keeping it closed, and his body is "tethering" a part of his soul to reality so that he can continue to Astronomicon, make new Astropaths, and appear to small children in their nutrient paste breakfasts. Whatever is happening, it is implied to be extremely, extremely tenuous and breaking it for even a moment might shatter it forever. It's working, don't fix it.

2) The Golden Throne is reasonably large by human standards, but probably not larger than say a Titan. It is however much smaller than the last "Warp Rift" to open inside of an overly decadent, ambitious, and hubristic Empire which eventually became that little "Eye of Terror". A few warp rods are not going contain an explosion that could conceivably take out the entirety of Terra. Or it might. But no one is seriously going to test it. The Warp Pylons are also not quelling the Eye of Terror, because the Eye of Terror was formed long after the Necrons were defeated. All the Cadian Gates are doing is allowing for a stable passage in and out of the Eye of Terror. Also the Cadian Gates are breaking down.

3) As for why the Eldar haven't just shown up to help, you should read The Beast Arises series. In non-spoiler terms, the Emperor was building his own conduit into the Webway, so it isn't part of their existing network. Secondly, that conduit is now broken so the Eldar are not going to "open" it from the other side because that'll just cause more than a few problems for them. And they don't show up to help most of the time because no human is seriously going to believe that the Eldar are going to go before the Emperor and not try to kill Him. The Imperium literally relies on the dessicated nigh-corpse of a man sitting immobile for a mind-bogglingly long period of time. The Imperium was warring against the Eldar a lot before the Heresy, so they might be better off now than they were pre-Heresy.

4) Even if building a Null cage would work - are you sure that it won't just overload it? It's still technology, and it could still be used to bring very human Chaos marines through to target the cage and shoot it from the inside. You need complete, absolute, 100% denial of any Warp energy, which means you also can't be passing through it because then it's not completely sealed. In which case as soon as it breaks the entirety of the collected psyche of millions of years of suffering pours through into Terra. Again, not ideal.

Consider, the Sisters of Silence were deployed against the Thousand Sons. This was not a curbstomp battle for the Imperium, they were making progress, but then Magnus showed up and was so powerful he could overpower the "field" that the Sisters were generating, and even if he couldn't target them directly he could suck the air out from around them, compress the air above them to crush them, explode the ground beneath them... being Untouchable did not save them.

I think there are lots of reasons why it couldn't just be fixable, and part of it is that we don't know the exact nature of what happened. Magnus broke something, and the Imperium might never recover. If there's a way forward, it will probably be more difficult than piling some magic rocks in front of a hole and hoping that's fixed it.

Okay, let's try to tackle this:

1. Can see this.
2. It was sort of my thought that the Cadian Gate Pylons were preventing the further growth of the Eye; otherwise, every time I read something more like you said, it makes the "stable warp route" thing only sound terrible. If gives Abaddon exactly what he needs, to throw an army into the middle of everything, once he thinks his forces are big enough (and even though his masters SHOULD be able to drop his fleet ANYWHERE, being masters of the warp), and only really gives the Imperium a bit of foreknowledge on where the hammer will fall, and yet Abaddon IS trying to overload the pylon system, as if he finds them an inconvenience. Maybe it's just more the inconsistencies of writing, among the GW staff, but this has always confused me, a little.
3. I'm going to confess I might've been giving the Eldar "fanboy credit" they probably haven't earned. I certainly accept that they wouldn't just show up, on Terra, and offer to help, if they even could; they are, in most writings, capricious, self-serving *icks, and they weren't the ones who made the Webway, so maybe the even CAN'T fix it. I was more imagining if the Emperor's glory hole had actually gotten itself into the standing Webway, which would be allowing the daemons into that whole region of the decaying roads, then the Eldar might come across it from another path it now meets, and they'd try to plug it, to protect what they still have. On the other hand, if the Emperor's path DIDN'T reach the Webway, I suppose that might be why it's a gaping hole in to the warp, instead, while plenty of the Webway is in a bad way, and the "mighty" Eldar haven't shored those stretches up, either.
4. Yeah, I can see that, too.

There are two big problems with fixing the warp rift. At least it's only accessible after passing through a number of enormous fortified gates, so the general populace neither knows about the problem nor has to deal with it.

First, it was created as a result of catastrophic failure on the part of the Imperial Webway. The Imperial Webway itself was an attempt by the Emperor to backtunnel into the original Webway created by the Old Ones; but not being an Old One himself the Emperor instead had to make do with jury-rigging, slow ritual, and psychic brute force. So now that the Emperor's out of commission beyond propping up the Webway and helping to keep things under control to assist the Custodes, no one (or at least no one who'd be willing to help) has the knowledge or technology to actually repair the damage.

Second, the warp rift is a major salient of the Warp upon realspace. The forces of Chaos know on some level that if they can just break through to Terra on the other side, they can cheat their way into their endgame objective of controlling humanity like playthings after grabbing/corrupting the Imperial leadership and the Emperor. The Custodes know this too, which is why Chaos hasn't broken through yet, but regardless there are a lot of demons on the other side who would like nothing better than to make fashion accessories with your entrails. Any sort of repair team who went out there would have to be heavily defended.

That's not to say that it can't be done, mind you, but rather that it's **** difficult to pull off. The ideal solution would be to find some Old Ones who aren't hostile and to explain the problem to them, but good luck doing so between intolerance of xenos and finding Old Ones who are alive but not hostile. (My RT group managed this last session, but they're working with a less intolerant society and really had to work their way up to finding the Old Ones. Plus the whole tone of that campaign is "the crew gets up to some seriously crazy nonsense, news at 11"; we all understand that it's very much non-standard.)

Yep, I might've fanboyed a bit too much. I didn't even consider of Old Ones being left, and my brain sort of doubts that they are. I've got a story element of Isha still being alive, and a whole, convoluted plan to bring her back to the Eldar, from Nurgle, but there is no certainty if this would actually be a good thing for the Eldar (they'd have back another of their "Gods", whatever they truly were, and for whatever advantage that would be to them, now (she's their goddess of birth, but the Eldar gods aren't all-powerful), or if it is a trap (Nurgle has held for for millennia, possibly using all of his twisted, polluted skills to form diseases that could even strike down the immortal Eldar, through their own goddess of birth and fertility). She could come back, only to be the (unwitting? Does she even know?) harbinger of their final fall, and not even from Slaanesh (also some non-standard ).

Well, it is something I wish GW had hinted more at how to fix. Maybe I, sometimes, just get bogged down in the fluff that everything bad that happens is happening to Mankind, and I could babble off my list, but I promise, I won't . It just always seems like an infinite number of endless, catastrophe-level events, not even one of which can be in any way alleviated (grimdark?)

This was very much fun! Again, sorry to throw up a thread bit that doesn't even, really, have anything to do with Rogue Trader, per say, but sometimes it's just fun to babble the 40k fluff, and thank you very much for indulging me. Have a good one!

Those necron pilons only stabilised the warp (leading to the forming of the cadian gate), you would need a lot more of them to really shut of the warp.

Also shutting of the warp around Terra. Might not be the best plan. I'm no Fabricator general of Mars but I'd wager doing that would make 1) The Sol sytem unreachable via warp travel. 2) Shut off/obscure the astronomican and 3) probably F up the Emperor in some way.

There's a necron device in one of the Word bearers novels that can shut of a star sytem from the warp, but the 'crons don't wanna share.

what if the Emperor tried to seal the warp rift.

Emperor: "there is a draft in here! I can feel it in my bones. Why haven't you closed that **** rift yet?"

Custodes: "I don't know my liege, I'll contact the work crews."

Work crews: "We're being eaten by daemons!"

Custodes: "O-o-owkay. Maybe the eldar have more luck on their end in the webway."

Eldar: "We're being eaten by daemons! Bloody mon keigh with your shoddy built off ramp on our beatifull webw-"

Custodes: "No luck sire!"

Emperor: "Bah! and all this thanks to my born-in-a-barn, letting-the-door-open, son Magnus!"

what if the Emperor tried to seal the warp rift.

Emperor: "there is a draft in here! I can feel it in my bones. Why haven't you closed that **** rift yet?"

Custodes: "I don't know my liege, I'll contact the work crews."

Work crews: "We're being eaten by daemons!"

Custodes: "O-o-owkay. Maybe the eldar have more luck on their end in the webway."

Eldar: "We're being eaten by daemons! Bloody mon keigh with your shoddy built off ramp on our beatifull webw-"

Custodes: "No luck sire!"

Emperor: "Bah! and all this thanks to my born-in-a-barn, letting-the-door-open, son Magnus!"

Because I had to:

Note, mature language warning!

Thanks for the video; it was a fun little watch. Sort of makes me wonder, if GW ever DID think to move the story along, if Magnus, among all the traitor Primarchs, could maybe sort of come back, as it were? He'd never be trusted, but he's never really done some of the crazy, terrible stuff, just for the lolz, that some of his brothers have, he was, at least partially, more tricked into joining Chaos, than actually saw good in it (the Emperor was just a bit of a tool, is all), and he might even be able to assist with the warp rift. Tzeentch would try to screw it up, or Just as Planned some other way, but... Probably still one of my favorite Primarchs; shame the Thousand Sons are sort of a crappy force, in 40k. Seeing as he blew his way in once, it also seems to me that Magnus should be able to get into the throne room, possibly whenever he wants...

From the perspective of the narrative they'd have to tread lightly on that. See, while actually moving the story along in some way does need to happen (currently we're stuck with GW carving up fractally smaller sections of M41), the overarching point of the narrative as a whole is to support Faction A beating on Faction B. 40K is a wargame first and foremost, and while GW believes that a marketing department is "otiose in a niche" they at least understand that customers should be able to have their (expensive) armies beat on each other without going through a lot of contortions if they want the story to line up.

This is somewhat belied by the fact that there are about as many presumably cooperative Imperial "factions" as there are non-Imperial factions, but at the least the principle is sound.