"The colours are balanced against each other- each has two associated and two opposed colours. According to our best theories, a sixth colour would also need to have two associated and two opposed colours. Since association and opposition are symmetrical relationships, that would only be possible if there were not one but five unknown colors, independent of the ones we know of. And so far as we've found, the five colors and their various combinations encompass all conceptual space. There is such a thing as colorless mana, but it's simply conceptually neutral whereas each color of mana is conceptually aligned. Of course, our theories wouldn't have predicted elementalist, enchantment, or arcanist mana, so our theories are clearly imperfect. And there are entities which seem to exist outside of the conceptual space we've been able to understand and around which colorless mana behaves almost as though it had a sixth color."

"Entities?"

Jace's responds after a pause, and in a sad tone.

"They're known as Eldrazi, and they eat worlds. When I encountered them, they had recently escaped imprisonment on the plane Zendikar and were in the process of consuming it. They reproduce rapidly, grow to enormous sizes, and are capable of considerable cunning and a diverse array of magical powers including mind control and a sort of magic resistance."

"They eat worlds? What the fuck."

"The multiverse contains great wonders but also terrible dangers. The Eldrazi are the worst I have encountered personally."

"Have they been stopped?"

"No."

"How does one stop them."

"Their capacity for countermagic is limited, and individual eldrazi can be destroyed. The main issues were the numbers of the lesser eldrazi, the size of the greater ones, and the way everything and everyone we bring against them will wither and disintegrate along with the plane."

"And is the thing where multiple universes existing is a secret stopping people from organising against them?"

"The problem is more the limitations and unpredictability of interworld travel. I've reported the awakening of the Eldrazi to the Boros Guild, who are responsible for responding to emergencies. But in the current political climate that might not be enough evidence to get them to dispatch one of their two planeswalkers even for reconnaissance. It would probably do more good to report it to the Academy of Tolaria West on Dominaria, whose headmaster has successfully dealt with multiversal threats before. But he's also notoriously unpredictable and dealt with one of those threats in part by destroying two planes and plunging another into an ice age, so I've been putting that off."

"...so he sounds like a problem at least as bad as these Eldrazi themselves."

"I don't think he would destroy planes except to deal with something comparably bad. If the things he did really were the only way to defeat the Phyrexians, as he claims, they were worth it; it's because of the Phyrexians that I say the Eldrazi are the worst danger I've encountered rather than the worst I know of. And last I heard he seemed to be enjoying retirement rather than plotting anything, although his plots have historically been convoluted enough that we may never know that for sure. But the Eldrazi are the sort of thing he might come out of retirement for, for good or for ill."

"...how bad are these Phyrexians, then?"

"Fortunately, so far as I know the Phyrexians aren't, anymore.

But Phyrexia was the domain of the wizard Yawgmoth, and he tried to shape it into his vision of an ideal world. That being a world where love and mercy were eliminated, where the weak utterly dominated by and subservient to the strong in their every thought, action and bodily process, and where the slightest failure was punished with immense suffering. He also sought to spread it across the multiverse, and came close to conquering Dominaria.

To be fair, he wasn't able to fully implement his vision even in the planes he created. It's possible that in practice the worlds he conquered wouldn't have become much worse than your typical totalitarian dictatorship apart from the unusual amounts of torture and rather absurd amounts of mutilation Yawgmoth was fond of. So it might have been an exaggeration to suggest that Phyrexia was worse than the Eldrazi."

"Well. At least there's only one world-consuming problem right now."

"Only one I know of. I've only been to nine planes myself and the multiverse isn't even known to be finite."

Nod. "Why is interworld travel unpredictable?"

"Time passes differently in different worlds, and we can't reliably predict how and when time ratios will shift. And the landscape of the planes is constantly shifting and difficult to map, and the spaces between them are chaotic and confusing, and take precise timing and control to navigate properly, with failure potentially leaving you in some unfamiliar plane. There are artifacts which create stable interworld passages, but the technology to make and to reconfigure them was lost."

and then, with sudden enthusiasm;

"maybe you could change that?"

"—you know, I bet I could."

"The only planar portal currently on Ravnica is kept at Nivix, the capital of the Izzet League. They probably won't permit a non-member to experiment on it, but asking for permission could give me more opportunities to read their minds. We could try to get you past their security without that permission, but Izzet labs can be dangerous to navigate even with the help of the League. It would be safer to go to Dominaria and inquire after one of the portals there, but it would mean being away from Ravnica for an unpredictable length of time and possibly missing whatever the Izzet are planning."

"Why are you so interested in whatever the Izzet are planning and not in ending the world-eating monstrosities?"

"Because I at least mostly know how to keep myself safe from the Izzet, and because Ravnica, unlike Zendikar, is my home.

And because I know there are pieces of the puzzle I'm missing here, and that bothers me."

"The world-eating monstrosities are probably gonna come for Ravnica, too."

"Eventually, yes. If I'd thought I stood a chance against them I'd still be fighting them.

You might be useful against them, but they might be able to take control of you. We should probably sit down and figure out what you can do that would be useful. Setting up planar portals is obviously one thing you can do. You also seem to be able to collect mana without using a bond, which might let us bring a lot of mana against the Eldrazi at once. And there are other lost magics you might be able to replicate. Shall we go to my place so we can take notes?"