I want to ask your opinion on why Mirrodin is such a trainwreck and what should be changed/retconed to make it work.
The points I care most about are:
- How Karn transported phyrexian oil there;
- The whole taking life from other planes thing;
- Why there were still Mirrans at the end;

It's not, I love it and it's wonderful. Unless you mean scars.

The real problem with Mirrodin is that it's an incredibly boring world from a worldbuilding perspective.

You have five areas (one for each color) and five races (one for each colors) and five different human groups (one for each color)... And the artifact theme just isn't enough to carry the entire world.

The best thing that could have happened to it was a Phyrexian invasion to shake things up.

In the original interpretation, it was Jeska/Karona that did it.
Of course, that causes issues what with the nullity of Karona's Bogus Journey.

Thanks, I never knew that. It seems that Karona always mess up stuff...

In some ways, I find the simplicity appealing, because it allowed for some truly beautiful worldbuilding in regards to each different culture (except the Black faction).

But indeed it just doesn't hold a candle to some of Magic's finest sets.

I see where you're coming from. But I tend to think about it like this: If someone submitted the plane to the Expanded Multiverse, would it get voted in. And Mirrodin probably wouldn't on account of being too simple.

I find it ironic, and a little sad, that with all of Mirrodin's problems from a world-building and story-telling standpoint, it remains one of the best-selling sets in Magic's history. I believe it's second only to Return to Ravnica, though I couldn't find the figures to back that up, so I could well be wrong. That's... really unfortunate.

The worldbuilding is a little bland but the story of creation of Mirrodin is pretty sweet, and I love everything about memnarch.

I'm actually pretty fond of Memnarch, as well, it's just there are so many plot-holes when it comes to Mirrodin, and even more when you fast-foward to Scars-era Mirrodin. As a player, I really enjoyed the set, but as a Vorthos, I really feel it could have been handled much better.

I think the hole one of the best selling sets in mtg history thing probably came from how overpowered some of the cards were.

What are all the holes in the story?

I think that Mirrodin broke sales records even before the broken cards in Darksteel came out. I have no idea how I would confirm that though.
Part of the reason is probably because it was the most unique plane of its day. Magic had already experimented with other settings, but they were all pretty similar to Dominaria. Mirrodin sold on novelty value (and of course power level).

The 5 regions, 5 races thing is super lazy, but it kind of works with the artificialness of the plane. If they played that angle up a little more it would've been awesome.

I would think that part of the appeal of Mirrodin was that it showed how unique Magic can get while still staying both fantasy and Magic. Mirrodin skirted the lines of what most would consider sci-fi (high fantasy sci-fi like Doctor Who or Avatar [the James Cameron movie]) - with its total metal everything and little robots everywhere - without outright losing what makes it Magic (the five colors, the references to planes and the multiverse, the representations and mechanics) or rejecting fantasy as its base.

Actually, from that perspective, having the [five areas = five colors] thing may have been a conscious choice to keep from crossing too far into the high science fiction territory. I'm not necessarily saying it was a good decision or that it was handled exceptionally well, but they may have thought they needed to make the five colors more obvious to counteract the metallic robotic feel.

Honestly, the "five colors, five areas" thing is not a major concern of mine. My problems with Mirrodin, in no particular order, are:

Please, Raven. You of all people know the answers to that one:

It's worth noting that some of these solutions are extrapolated. It doesn't, to my knowledge, explicitly say anywhere exactly how the temporal dynamics worked, but it fits with what we know.

...Of course, then Scars basically screwed the timeline up again completely because everything Mirrodin and Karona touch turns to temporal disaster. Sigh.

The oil was probably a late-game weapon that never quite made it to use in the Invasion. It's certainly not glistening oil of the type we saw before. There was no indication of it having the properties it showed during Scars. Also I'm pretty sure it was, y'know, glistening and golden rather than black as on Mirrodin, so yeah. But anyway, it was prooobably a nanoweapon designed late in the war that was never fully employed and didn't have enough material to work with (it seems to require both metal and power--i.e. the huge mana core of Mirrodin), we know that it was tracked there by Karn and it was proooobably brought there either from Dominaria or from Phyrexia itself (because the other explanation--that it came from his heartstone--is stupid and makes no sense). We know for certain that it was Karn that tracked it there, though--that's why he's wandering around now looking for other planes that he infected.

As for how it grew, well, it apparently contained blueprints for Phyrexian creatures. Once Memnarch was gone, and his world-warping madness no longer protected Mirrodin, the oil began to rapidly mutate the plane. The Nim were a huge nesting site for the infection, of course, and once it got lodged in other areas it really was only a matter of time before they overran the plane. They already had access, of course, to the power of the core, and all of Memnarch's creation.

At that point, it would've been easy to start assembling vats from the blueprints contained within the oil. After a very short while, very few New Phyrexians were probably culled from the existing population.

One thing I'd love to know, though, is how the Praetors were created and rose to power. I'd read the crap out of an Elish Norn origin story.

Indeed, but Scars seems to depict the infection as only a significant menace after the phyrexians deliberately began, well, infecting. Surely there would have been previous infections, but they were rare enough that nobody raised an eyebrow until the end of the world began to fester beneath their feet.


It could also be that mirrans in general are also ungodly stupid. Which wouldn't surprise me, sadly, because it was semi-confirmed with the vedalken.