I remember during GDS2 one of the designers had a mechanic that created a token that was a copy of the creature with swapped P/T. One of the complaints was it meant too many tokens would need to be made.
Now we have offspring, embalm, and eternalize. Does that make the complaints for the design less valid?

The bar to do so is high, but lower than it once was.

Why was it decided that the tokens created by offspring would keep their mana costs, unlike the tokens created by embalm/eternalize?

It was a templating decision to lessen the word count, I believe.

I know people have mixed feelings on Modern Horizon sets and how they impact Modern, but I just want to say that from a design standpoint the cards are simply glorious. A card with both Ferocious and Eternalize is just so cool and all the MH sets have things along those lines. High fives to all the people that make these sorts of combinations.

High fives will be passed along.

It's been a while, but why did Embalm and Eternalize make the tokens with no mana cost?

We didn’t want to put mana costs on the tokens as we thought it would create confusion.

Wait, if black/green are the self reanimating colors and Eternal Dragon is a break, then why does white get mechanics like Embalm, Eternalize and Disturb, on high volume even?

White can reanimate other creatures. It’s number two at reanimating. It’s not supposed to be on creatures reanimating themselves as that’s black and green (and red on Phoenixes).We let mechanics do it which is why the three above mechanics did it, but we don’t let white do it on individual cards much like blue got Embalm but doesn’t get it on individual creatures.

My thoughts on Disturbed: it's an interesting mechanic in a vacuum, but it's hampered by the fact that this is like the fourth or fifth time we've gotten "Flashback... But for Creatures!" (Unearth, Embalm, Eternalize, kind of Escape) and it shows up alongside actual Flashback, which saps a lot of the excitement because it feels like a rehash. Add that to it eating up DFC space that feels like it could have been spent on resonant tropes and it seems lackluster in my opinion.

Why is people dying and coming back as ghosts not resonant?

Good morning Mark. I hope things are well with you. I have a request, one that I assume is not under your control but that you could pass on to those who do control it. Specifically, would it be possible to include in the bundles a packet of all the tokens created by the cards in the given set (as was done with Amonkhet's and Hour of Devastation's Embalm and Eternalize tokens)? As a token lover & user, it is often nice to have more but it can get difficult to collect. Many thanks.

I’ll pass along the request.

(On Eternalize and Megamorph vs Embalm and Morph) "The frustrating part is we weren’t trying to pass either of those two mechanics off as new mechanics. We were just trying to tweak them slightly to fit the story." I think that when people see a new keyword they get excited, but when they see it is so similar to an old one they judge it harshly. The way that exert kept the same name but got new functionality is exciting, but eternalize being a tweak of embalm is a let-down.

Let’s ask you all. Is tweaking a mechanic and giving it a new name for flavor and slightly altered mechanics something we should or shouldn’t be doing?

It’s weird that threshold is a 9 on storm scale when Eternalize is an 8. If Eternalize is both narrow and unpopular, and only works on the plane if Amonkhet, how is it better off than threshold, which seems like a perfectly fine mechanic (just count to 7, works with graveyard themes, and creatures dying).

Maybe Eternalize should be a 9, but I’m skeptical of threshold coming back. (Shadows over Innistrad messed with delirium, a twist on threshold, and that didn’t go great.) But hey, I never say never. It could happen.

I feel like Eternalize is the most setting-specific mechanic R&D has ever designed (it only really fits on Amonkhet during the Hours). Do you agree?

It’s up there.