So for a while now I've been thinking about making a cube entirely out of custom cards. YmtC is a hobby that has occupied my life for 14 years now, and I'd like to translate it into something tangible. Very recently I got the idea, somewhat inspired by a post I saw, to make a cube using the artwork of Lorwyn and Shadowmoor block. It's is a plane I very much appreciate, butit doesn't have a limited format I particularly want to re-create, so I'm going to do some very drastic overhauls to make it more in line with the gameplay patterns I favor, while still trying to capture some of the older gameplay feel. All that said, I'm still very much in the "figuring things out" phase, this is just a rough outline of what makes sense to me. I want to capture the larger thematic aspects of the set while still offering compelling games.
Kithkin
My beautiful little midget men. Don't mind all the normies calling you creepy, I will always love you.
The defining feature of Kithkin is the thoughtweft, a feature that makes them a quasi-hivemind. In the Lorwyn era they are homely hobbits who welcome travelers to their clachans, contrasted with their highly xenophobic Shadowmoor-counterpart who are only able to trust the people whose inner voices they can hear through the thoughtweft.
Kithkin are sort of a David archetype, taking down Goliaths with cooperation and wit. I'm thinking of emphasizing this through combat-trickery, flash creatures, and go-wide/token cards. They also have some superstitious tendencies that can play into a few different things.
Merrow
The Lorwyn merfolk are many things; merchants, taxi drivers, deep-sea divers and rivermancers. The Shadowmoor merfolk on the other hand are just dickheads. In the original set, they have this really strange tapping-matters theme going on that I'm not sure where comes from, plus some mandatory islandwalking things. For my cube, I think I want to emphasize their river-mastery through phasing, letting them slip in and out of combat, along with some other evasive mechanics. The merrow make their own roads.
I'm not sure how to play into their more mercantile proclivities. One way to go about it is using the various artifact-tokens like treasures. Another consideration I've had is giving them some topdeck matter themes, scrying being representative of their extensive river-based information network.
Elves
Elves of Lorwyn are unapologetic nazis to a degree that wotc had to retcon Nissa's interaction with them to protect her mass appeal. They pair unrealistic beauty standards with a crusade against anything they deem ugly. Come Shadowmoor, when the entire world is ugly, they make it their goal to preserve what little beauty is left. They also have like, some plant magic.
Defining beauty in magic in a way that can be designed around is a pretty challenging concept. Gilt-Leaf Winnower is a cool card, but not something to base a tribal identity around. I think the BG elves of Lorwyn are best portrayed in a quasi-aristocrat shell exploiting your pawns for the benefit of your queens, paired with aggressively hostile interaction. They hunt for sport, all things considered. The GW Shadowmoor elves are a bit more tricky, but I think it makes sense for them to sacrifice themselves for the benefit of your other creatures as a role-reversal, and play protection spells instead of disruptive one.
Giants
Giants are mechanically pretty simple. They are, for the most part, just really big. The Lorwyn half of them are renowned as exceptionally wise, while the Shadowmoor ones are slumbering behemoths who have slept so long they have almost merged with the terrain. Now, making big creatures is very easy. Making people play a lot of big creatures and not have it be a trainwreck, is very hard, and I haven't figured out how to solve it yet. I almost want to make some giants that have affinity for other giants in your hand. The "reveal a dragon" cards from Tarkir are quite interesting, and I might play around a bit with that space, but all things considered I don't know what I want a "giant lord" to look like. They're not really a tribe that thematically lend themselves to alternate costs like the Elementals do with Evoke, which make them a lot easier to get critical mass with.
Boggarts
The goblins of Lorwyn are hedonists who want to experience every sensation there is. The Shadowmoor ones are similar, except they mostly care about those that fall under the category of violence and eating. Impulse-draw and other "use-it-or-lose-it" mechanics sort of gamify this, but I can't say I'm confident in how I want to do the boggarts. The Shadowmoor ones obviously want to attack a lot, but their precursors I'm less sure about. If I introduce some trinket-artifacts then they might key off activating those.
Faeries
Faeries have a pretty solid identity, they're annoying and often play at instant-speed. They're like kithkin, except they care less about combat and more about disrupting other aspects of the game, and they all have flying. They're notably also the only race unaffected by the aurora, so they probably won't get much in terms of day/night benefits.
Treefolk
Treefolk are kind of funny, as they have the same color profile as the Elves, except swapped between the two sets. They cared about toughness and lands in the original sets, and I don't intend to change that, although their land focus might be less forest-specific just for gameplay purposes.
Elementals
Evoke is a cool mechanic, I'll keep using it. Shadowmoor elementals will Evoke with non-mana costs to represent the resource scarcity.
Flamekin
The waifu-able burning subsection of elementals, the Flamekin is a spiritual species on a journey of discovery both of the world and the inner self. The pilgrim Ashling was destined to share the power of a great elemental with her kin to carry them through the darkness of Shadowmoor. Instead she cucked all of them and took all of the power for herself, which is why the cinders are all assmad, at Ashling and the entire rest of the world in a weirdly literal and spite-driven "eat the rich" philosophy.
I haven't thought too much about the Flamekin. In original Lorwyn they have some weird kind of activated-ability theme going on. I think I want to give them some sort of explosive blaze-of-glory gameplay style. Meanwhile the cinders will probably have some kind of stax thing going on.
Shapeshifters
Lorwyn ones are changelings and are designed to cross-pollinate between tribal payoffs, they are an amalgamation of tribes. The shadowmoor ones are mimics, shifting between individual distinct ones. I'm not too clear on what specific changelings I want to make, but the mimics will probably have temporary clone effects.
Morningtide also has a class-tribal aspect to it of wizards/shamans/soldiers/rogues/warriors that I will probably also make a few cards for, because I like the layered tribal buffalo-aspect. Lorwyn block had a bit of an issue where you had to layer different linear-scaling abilities to different creature types, but I think if you design your tribal payoffs a bit differently you can avoid that issue.
Structurally I'm still largely undecided on how big I want it to be, but I think I want a fairly robust core of role-players and a large set of occasionals to spice it up with more niche build-around effects, mostly because this way I get to make a bunch more cards.
Broad Strokes
To capture the theme of the Great Aurora, I think I'm going to introduce the day/night cycle as a core element of the gameplay. When you win the die roll, you can either choose the starting player, or whether the game starts at day or night, and forfeit the other decision to the opponent. Some cards from Lorwyn will care about it being day, and some cards from Shadowmoor will care about it being night, and then some few individual cards might get more intricate. I'm going to restrain myself from making custom double-faced cards, even though there are some great design options; I don't want players to have to do more than just read the card.Lorwyn
A sunlit plane of everlasting spring, Lorwyn is almost disgustingly cheerful and out-of-place for a game about violent mage duels. As the designated "day" plane, double-spelling is heavily encouraged, which means the cards will naturally encourage high-velocity gameplay styles. Specifically how I want to facilitate this mechanically I'm not entirely sure on, but Evoke is at least excellent here at offering flexible casting-points. The other large focal point of Lorwyn is the tribal component. I want to retain that identity, but make it more incidentally than overtly tribal in the form of higher-floor lower-ceiling payoffs. The Tribal card-type is staying, expect to see it used liberally.Shadowmoor
No longer Mr. Nice Plane, Shadowmoor is here with it's anxiety-filled somber atmosphere. Mechanically, this block is a bit of an oddball. Wither is an excellent portrayal of the downward spiral that is the existence of this plane, but translates poorly to games outside of retail limited, and the hybrid-overloaded color-matters theme that pervades the set is interesting, but also fairly out of place. I really like hybrid cards, and will make them a prominent part of the cube, with some color-matters cards to provide interesting deckbuilding considerations, but it will be largely auxiliary rather than a core mechanic. Given that it's the "night" side of the set, flash spells and instants are natural ways to flip the switch, and help play into the spooky atmosphere of the set contrasted to the "look at all my cool plays"-side of Lorwyn. I will probably give a greater emphasis on the graveyard to contrast with more board-centered cards of its counterpart; Delirium is a cool incentive to draft Tribal cards, and Delve is inherently one of my favorite mechanics. I want to explore some themes of resource-scarcity as well to play up the atmosphere of Shadowmoor, still tinkering around on that one for specifically what to do.Tribes
Lorwyn makes an attempt at giving mechanical identities to the different tribes with varying degrees of success, and I want to make sure I really do a good job with these, which is looking to be a real challenge.Kithkin 
My beautiful little midget men. Don't mind all the normies calling you creepy, I will always love you.The defining feature of Kithkin is the thoughtweft, a feature that makes them a quasi-hivemind. In the Lorwyn era they are homely hobbits who welcome travelers to their clachans, contrasted with their highly xenophobic Shadowmoor-counterpart who are only able to trust the people whose inner voices they can hear through the thoughtweft.
Kithkin are sort of a David archetype, taking down Goliaths with cooperation and wit. I'm thinking of emphasizing this through combat-trickery, flash creatures, and go-wide/token cards. They also have some superstitious tendencies that can play into a few different things.
Merrow
The Lorwyn merfolk are many things; merchants, taxi drivers, deep-sea divers and rivermancers. The Shadowmoor merfolk on the other hand are just dickheads. In the original set, they have this really strange tapping-matters theme going on that I'm not sure where comes from, plus some mandatory islandwalking things. For my cube, I think I want to emphasize their river-mastery through phasing, letting them slip in and out of combat, along with some other evasive mechanics. The merrow make their own roads.I'm not sure how to play into their more mercantile proclivities. One way to go about it is using the various artifact-tokens like treasures. Another consideration I've had is giving them some topdeck matter themes, scrying being representative of their extensive river-based information network.
Elves
Elves of Lorwyn are unapologetic nazis to a degree that wotc had to retcon Nissa's interaction with them to protect her mass appeal. They pair unrealistic beauty standards with a crusade against anything they deem ugly. Come Shadowmoor, when the entire world is ugly, they make it their goal to preserve what little beauty is left. They also have like, some plant magic.Defining beauty in magic in a way that can be designed around is a pretty challenging concept. Gilt-Leaf Winnower is a cool card, but not something to base a tribal identity around. I think the BG elves of Lorwyn are best portrayed in a quasi-aristocrat shell exploiting your pawns for the benefit of your queens, paired with aggressively hostile interaction. They hunt for sport, all things considered. The GW Shadowmoor elves are a bit more tricky, but I think it makes sense for them to sacrifice themselves for the benefit of your other creatures as a role-reversal, and play protection spells instead of disruptive one.
Giants
Giants are mechanically pretty simple. They are, for the most part, just really big. The Lorwyn half of them are renowned as exceptionally wise, while the Shadowmoor ones are slumbering behemoths who have slept so long they have almost merged with the terrain. Now, making big creatures is very easy. Making people play a lot of big creatures and not have it be a trainwreck, is very hard, and I haven't figured out how to solve it yet. I almost want to make some giants that have affinity for other giants in your hand. The "reveal a dragon" cards from Tarkir are quite interesting, and I might play around a bit with that space, but all things considered I don't know what I want a "giant lord" to look like. They're not really a tribe that thematically lend themselves to alternate costs like the Elementals do with Evoke, which make them a lot easier to get critical mass with.Boggarts
The goblins of Lorwyn are hedonists who want to experience every sensation there is. The Shadowmoor ones are similar, except they mostly care about those that fall under the category of violence and eating. Impulse-draw and other "use-it-or-lose-it" mechanics sort of gamify this, but I can't say I'm confident in how I want to do the boggarts. The Shadowmoor ones obviously want to attack a lot, but their precursors I'm less sure about. If I introduce some trinket-artifacts then they might key off activating those.Faeries
Faeries have a pretty solid identity, they're annoying and often play at instant-speed. They're like kithkin, except they care less about combat and more about disrupting other aspects of the game, and they all have flying. They're notably also the only race unaffected by the aurora, so they probably won't get much in terms of day/night benefits.Treefolk
Treefolk are kind of funny, as they have the same color profile as the Elves, except swapped between the two sets. They cared about toughness and lands in the original sets, and I don't intend to change that, although their land focus might be less forest-specific just for gameplay purposes.Elementals
Evoke is a cool mechanic, I'll keep using it. Shadowmoor elementals will Evoke with non-mana costs to represent the resource scarcity.Flamekin
The waifu-able burning subsection of elementals, the Flamekin is a spiritual species on a journey of discovery both of the world and the inner self. The pilgrim Ashling was destined to share the power of a great elemental with her kin to carry them through the darkness of Shadowmoor. Instead she cucked all of them and took all of the power for herself, which is why the cinders are all assmad, at Ashling and the entire rest of the world in a weirdly literal and spite-driven "eat the rich" philosophy.I haven't thought too much about the Flamekin. In original Lorwyn they have some weird kind of activated-ability theme going on. I think I want to give them some sort of explosive blaze-of-glory gameplay style. Meanwhile the cinders will probably have some kind of stax thing going on.
Shapeshifters
Lorwyn ones are changelings and are designed to cross-pollinate between tribal payoffs, they are an amalgamation of tribes. The shadowmoor ones are mimics, shifting between individual distinct ones. I'm not too clear on what specific changelings I want to make, but the mimics will probably have temporary clone effects.Morningtide also has a class-tribal aspect to it of wizards/shamans/soldiers/rogues/warriors that I will probably also make a few cards for, because I like the layered tribal buffalo-aspect. Lorwyn block had a bit of an issue where you had to layer different linear-scaling abilities to different creature types, but I think if you design your tribal payoffs a bit differently you can avoid that issue.
Structurally I'm still largely undecided on how big I want it to be, but I think I want a fairly robust core of role-players and a large set of occasionals to spice it up with more niche build-around effects, mostly because this way I get to make a bunch more cards.
