Do you know who first came up with the character of Urza?

I think Richard came up with the name. The East Coast Playtesters (Skaff Elias, Jim Lin, Dave Petty & Chris Page) came up with The Brothers’ War and the first characterization of Urza.

Hello Mark, yesterday was my birthday(a little late to post, but I'll try), could I get some trivia on one of my favorite characters, Mishra?

Richard Garfield included proper names in Alpha to give the spell’s more flavor. The Antiquities design team (Skaff Elias, Jim Lin, Dave Petty, Chris Page & Joel Mick) came up with the idea of crafting a story using some of the names as the main characters. Happy Birthday!

I recently picked up an Ice Age play test Disenchant (super thin, white both sides, that sort of thing). Who all would have played with this card during its use? Not sure where to look to find he Ice Age play test team.

The Ice Age design team was who we call the East Coast Playtesters (Skaff Elias, Jim Lin, Dave Petty and Chris Page). Ice Age is early enough that there wasn’t yet a full development process set up, so besides the design.team, I assume Richard and some very early R&D team members playtested it.

In the beginning, a lot of set were designed by playtesting team. East Coast playtester; Antiquities + Ice Age Bridge Club; Mirage + Visions Peter Adkison rpg friends; Legends + Homeland What's the context behind Fallen Empire? Was it rushed like Arabian Night? It feel so weird and different than the other sets of its time. It is also very cohesive in flavor.

Fallen Empires was designed by the East Coast Playtesters (Skaff Elias, Jim Lin, Dave Petty & Chris Page), the same design team that did Antiquities, Ice Age & Alliances.

It's my birthday! Can I get some fun facts about my favourite planeswalkers Venser and Urza?

I believe when Richard made up the name Urza on card’s in Alpha (Urza’s Glasses & Urza’s Sunglasses) he didn’t have a particular character in mind. The character was created by the Antiquities design team (Skaff Elias, Jim Lin, Dave Petty, Chris Page and Joel Mick) who made the story of the Brothers War.Happy Birthday!

Hey Mark! It's by birthday. Can I get some trivia on my favorite ancient race, the Thran?

The Antiquities design team (Skaff Elias, Jim Lin, Dave Petty, Chris Page & Joel Mick), who also wrote the story, liked the idea that just as we’re archeologists digging up the story of the Brother’s War, Urza and Mishra’s story starts with them digging up a civilization older than them. That’s where the Thran came from. Happy Birthday!

What was Spectral Chaos?

When Magic first was coming out, Richard Garfield asked his play test groups to each design a set. The East Coast Playtesters (Skaff Elias, Jim Lin, Dave Petty & Chris Page) made a set called Ice Age that eventually became, well, Ice Age.The group Richard met through a bridge group (Bill Rose, Joel Mick, Charlie Catino, Don Felice, Howard Kahlenberg & Elliot Segal) made a set called Menagerie that eventually became the sets Mirage and Visions.A play tester named Barry Reich (who played the very first game of Magic with Richard) went out on his own and made a set called Spectral Chaos focusing on a multicolor theme (note that was before Legends existed so he had come up with multicolor on his own). When we were designing Invasion, we looked to Barry’s set and took some cards and a mechanic (Domain, codenamed “Barry’s mechanic). If you’ve ever heard of Barry’s Land, this is the Barry who is being referenced.

Since we all talking about disease/illness in black. Who designed Pox and Small Pox cards?

The first Pox was made during Ice Age so it was made by some combination of Skaff Elias, Jim Lin, Dave Petty and Chris Page. Smallpox was made in Time Spiral by Aaron Forsythe and myself if I remember correctly.

Who is the person that created the original Thallids and Saprolings? Both the mechanics and flavour?

One or more of the East Coast Playtesters (Skaff Elias, Jim Lin, Chris Page & Dave Petty).

Whom would you put on MtG's Mount Rushmore? (besides Richard Garfield, he gets his own Andes)

That is a very difficult question. The three people that have had the biggest longterm impact on Magic have been Richard Garfield, Bill Rose and myself. The fourth person is a tougher call as there are many people who I feel could rightfully go in that slot: Skaff Elias, Mike Elliott, Randy Buehler, Aaron Forsythe, Elaine Chase. If forced, I guess I go with Aaron Forsythe.