You could make an eternal Giant Fan variant that removes a counter from one thing and adds a counter to another *of a type that's already on it*, right? That's just Proliferate-adjacent technology which we've had for years. The issue only arises when you make the card able to care about arbitrary counters the card *might* be able to have?

Yes, you can create another of a counter already on a card. Understanding potential is much more difficult.

"Put a counter on a card that adapts to the kind of counter the card refers to (such as Giant Fan) is also squarely in acorn territory." By which you mean, the rules can't handle it, not because it would be overpowered? I'm curious as to why that is.

The rules can’t handle it. It’s not overpowered. Being very powerful doesn’t keep you from being eternal.

I just saw a collection of 7 screenshots from 2011 thru 2018 from this blog where you repeatedly shoot down the idea of doing mtg crossovers. You said "We think it's important that Magic is one cohesive game, and not a hodge podge of different things." This hurts to hear because it's verbatim sentiment that has been expressed to you about UB which you shot down as unreasonable, and you never addressed the contradiction. I know things change, but how can we trust what you say to us here?

I’ve never said anyone’s feelings are unreasonable. People can and should feel justified believing whatever they want. My goal on this blog is to share with you my best sense of where Magic design is at that moment. Often Magic moves in directions I can’t predict. If you asked me ten years ago, as many people actually did, I wouldn’t have predicted Universes Beyond. But now that I’m knee deep in it, and I’ve seen a lot of data based on the ones we’ve released, I’m a convert. I believe it is something that will bring lots of happiness to Magic players. For example, I was in a playtest for a Marvel set the other day and it was one of the most fun playtests I’ve had in years. I’m a huge fan of Marvel, and, obviously, a giant fan of Magic, so bringing those two loves together is quite joyful. It really hammered home to me the power of Universes Beyond. Trust is a thing to be earned, and I’ve worked hard for twenty-eight years to form a trust with the players. I’ve never lied to you, but I have said things that I didn’t think would happen that did. Saying something not knowing the future isn’t lying. I 100% believed the thing I said when I said it. Also, I always stress that I couch future talk with the mindset that I don’t use my future knowledge. If I know we’re doing thing X next month, I’ll act as if I didn’t know that when asked about it, because it’s important for me to not ruin the surprise of what’s to come. This is much more like not telling someone they’re having a surprise party than straight up lying, but yes, whatever you want to call it, me not ruining future surprises is something I do regularly on this blog, and I’m totally transparent that I do it.

Couldn't you make Giant Fan work in black border the same way Reflecting Pool does, "if an ability of the second permanent could produce any type of counter"?

Producing a type of counter is more complex than producing a color of mana.

Giant Fan is perhaps one of the most intuitive un cards. What are the chances the comprehensive rules could change to accommodate it in black border? What specifically makes that difficult?

This is one of those cards I tried to make it black border, couldn’t, and made in an Un-set. The normal rules can’t handle the second sentence. (“If the second permanent refers to any kind of counter, the moved counter becomes one of those counters.”) Here’s the closest I was able to get in a normal set:

Do you think Giant Fan would qualify as eternal if reprinted?

No, to the best of my knowledge, the rules can’t do the “make it any token type referenced”.

Mark, I know we have Power Conduit, but could we see something like Giant Fan come to black boarder that effectively move other counter types? Or do you think with all the doubling effects now it would be problematic?

Black border has to say what the counter becomes. It can’t make it something mentioned on the card like Giant Fan. That’s why it’s Un.

Could Giant Fan work in black border?

Black border can do parts of it, but not all of it.

The wording on the ozolith really feels like it belongs in unstable, somehow giant fan feels more black boarder than it. Did it make the rules nerds in R&D explode?

Interestingly Giant Fan is the one that the rules have issue with. Turning a counter into a counter type referenced by the card it’s going on is easy to grok for humans, but messy inside the rules.

On politics in commander: people often associate politics with underhanded scheming and malicious intentions, but from political science pov, politics is any human interaction that accomplishes a collective goal. It doesn't have to be spoken. Communication often helps, some would say some of our worst political decisions were unspoken. But at a 4 player game, if someone is about to go off, even doing nothing is a collective decision that might accomplish a new game sooner.

Two things:1) People seem to be reading me as saying politics is bad. I’m not saying that. I think politics can add a fun, social level to a game, and there are games, like Diplomacy, where I really enjoy politics. I’m just trying to explain why I, personally, am not a giant fan of many multiplayer formats. It’s just a personal preference thing, not an indictment of it. And as Head Designer, I work hard with my team to make sure all our designs take Commander into account as it’s a very popular format.2) Poltics, from a gaming sense, is talking about how human interaction, silent and verbal, is used to influence game actions. If you’re playing a multiplayer format where players get to decide who to attack/target with spells, it has a political component. Once again, that’s not a bad thing. It’s just a description of what influences impact the game. It’s like me saying a game with dice rolling has randomization. It’s just me describing a game element not making commentary about it. (Again, me not liking it personally in one scenario isn’t me implying that it’s something that others aren’t supposed to enjoy.)