Goblin Artisans had another challenge I thought would work well as a multiverse design challenge: http://goblinartisans.blogspot.com/2020/09/weekend-design-challenge-092520.html

Roll five 6-sided dice (eg https://www.random.org/dice/?num=5) and look up the results in the following list:

First die: 1=white, 2=blue, 3=black, 4=red, 5=green, 6=multicolor

Second die: 1=artifact (doesn't need to use the color), 2=creature, 3=enchantment, 4=instant, 5=sorcery, 6=planeswalker

Third die: 1=common, 2-3=uncommon, 4-5=rare, 6=mythic

Fourth die: converted mana cost is what you rolled

Fifth die: 1=aggression, 2=control, 3=midrange, 4=ramp, 5=combo, 6=tempo. This is a bonus challenge, feel free to interpret it loosely.

My first entry is in the comments on GA.

My second has to be a 6-cost common black-ish control-ish artifact which is also quite uphill! :) Hm. We pretty much must be talked about limited, a constructed control deck is bound to play cheap spells and one expensive finisher which is some complicated rare thing.

All six-cost common artifacts to date have been creatures so a large serpent-y creature maybe with hexproof or something else that makes it a good finisher would make sense. I was surprised to see large creatures with hexproof at common, even at 7 mana, but apparently they printed that. I guess it's in a format where you don't usually get to seven mana.

Alternatively, Spine of Ish Sah is rare, but Universal Solvent and Scour from Existence are common, so it could be colorless removal, tweaked to cost 6. Which of those would be more useful to a limited control-ish deck? The non-creature would be more in the spirit of "artifact.

So I created Crushing Chamber.

­Banishing Shackles

Uncommon green 2-cost combo creature: Dangerlands Ranger

Hm. 3-drop white rare planeswalker, supporting midrange. Well, a lot of three drop rare planeswalker is probably midange-y. Although white leans aggro or control more. Planeswalkers are hard, not sure how to choose something that stands out.

Rare green 5-cost ramp instant: Manifest Terrain

I created Font of Misery yesterday, but I have forgotten the dice rolls that resulted in it.

Today I made Fog of Apathy and Ancient Storm.

Uncommon two-cost blue midrange enchantment: Glinting Reflection

You'll have to excuse me if I don't name my cards immediately. It's likely one or two of them might end up as a Name That Card card. I'll make sure to give proper names to these cards when that moment has passed.

(((NameReserved1)))
(((NameReserved2)))
(((NameReserved3)))

Alex made Expansive Acres

I made blue uncommon 2-cmc instant ramp: Twist

5-green 6-planeswalker 5-rare 2-cmc 4-ramp

Whew, what I rolled lines up for a pretty easy challenge. Ghoulbark, Arborist

1-4-5-2-4. White rare instant, CMC 2, ramp?! Created Expansive Acres.

I made Fountain of Restoration and The One Who Pursues.

On 10/4 I made Seventh Wind.

3-6-2-6-3: black uncommon planeswalker, CMC 6, midrange. Created Sorin, Fang of the Night.

1-5-1-5-6: white common sorcery, CMC 5, tempo. Created Rallying Clarion.

Midrange 5-cost GB midrange uncommon creature: Giant Bats

Black instant 4-cost common aggro: Exploit Weakness

Rare blue 1-cost enchantment for a control deck: Magical Hitch

Green rare midrange sorcery, cmc4. Cry of Desparation

2-1-1-3-5: common artifact, CMC 3, for a combo deck. I created Nuisance Engineer.

6-cost UG midrange planeswalker: Kiora, Greatcaller

Rare white tempo 4-cmc sorcery: Weight of Lethargy

Highland witch: Black 2 mana rare aggro creature