Hi, Mark.
Is it possible that something like a third expansion will be added to the Mirage block, just like Cold Snap was added to the Ice Age block over time? (since Weatherlight is like episode zero of the Rath cycle) (although I have a feeling Prophecy is the third)

Weatherlight was still the third block of the Mirage block. It does have flanking and phasing cards in it.

MaRo, I'm very curious how Prophecy or Homelands would do on your audience's ten-point scale.

Few would have played it. Both were a long time ago.

Would a prophecy token (as a set mechanic like blood) be an enchantment or an artifact?

I assume an enchantment token. A prophecy isn’t a tangible object.

How does vision design get players excited to return to the low powered, low complexity bore fest of Ixalan? Or for that matter any weakly or poorly received plane? Are these locations just thrown out with the garbage?

Prophecy and Dominaria took place on the same plane. Flavor of a world and power level are two very different vectors. We can return to a world that players liked the flavor of, without repeating mechanical mistakes.

Hello Mark, and happy new year….I am a fan of cycles you guys do in sets, especially when they are rare/mythic (ex. Praetors, Gods, Gearhulks, and many other rare/mythic cycles you guys have done over the years….wanted to know why art is assigned to different artists instead of one style of art (like when first planeswalkers were depicted by Alexci Briclot or I when Prophecy Avatars were drawn by RK Post?

We make many cycles, and five pieces is a lot for the alloted time, so we can’t always assign every cycle to one artist. We do try to do it where we think it’s most important.

What has the greatest difference between what it sold and the set before it did?

As a percentage difference? My guess is Prophecy and Invasion.

Hi mark, it's been over a month since my birthday, and I've been asking almost daily... But I understand these get buried/exiled! Please can I get some belated birthday trivia about Alexi Zephyr Mage and her cloak?

Alexi was part of a rare creature cycle in Prophecy where we made Spellshapers that had bigger effects but required discarding two cards. I don’t have much trivia beyond that. Sorry.Happy Belated Birthday!

You often talk about "good design" and go into great detail on your reasoning. Yet the last few years have been a nonstop parade of bans in Standard, sometimes only weeks after release, getting more and more frequent in Standard. I haven't seen anything like this before and have played since Prophecy. So, why should I believe you have any expertise on "good design" given this track record lately?

That is play design (doing things like balancing the power level of cards). I’m in charge of vision design (doing things like figuring out major themes and mechanics). Most of my design talk is about the work that I am my team do which is vision design.

It's my birthday! I was hoping I could get some trivia on one of my favorite sets Nemesis?

Mercadian Masques block is interesting in that each set takes place on a different plane. Mercadisn Masques is set on Mercadia, Nemesis is set on Rath, and Prophecy is set on Dominaria. Nemesis is also the first set to have a second version of a legendary creature (Crovax), but now changed due to the story. Happy Birthday!

What would you say is the best example of a good mechanic from a bad set? Does anything from Homelands, Kamigawa or Prophecy hold up?

Ninjitsu from Betrayers of Kamigawa is a good mechanic.