So a sphinx came and built a paradise upon asking questions. Each color strives to create the ultimate riddle, and then answer it to solve the everything. Each group has their own ways of meditation and searching for answers.
Be aware that this plane is massive, bright, and beautiful.
White: huge fields of grass and wheat in crop-circle-like patterns. Giant mazes that act like parks for everyone to visit and learn. Cities with architecture impossible in reality, escher style buildings everywhere. City maps are in riddles, and public transportation is madness. They believe community, love, and conversation will lead to their ultimate question. In addition to the cities they have special "libraries" where they keep the dead. Other people can asked those who have passed questions and learn from what they have learned.
Blue: large ocean full of puzzle piece shaped archipelagos, oceans filled with cephapids and Merfolk living in r'lyeh esque cities and temples of squids and krakens and etc. They believe that the ultimate question is hidden in the depths. Wheteher that be the ocean, space, or already in everyone's mind.
Black: swamps are the only place that isn't a traditional maze. Instead, the dangers come from witches and ghosts that produce a think fog that causes hallucinations. People visit from planes far and wide to ask them questions for all matter of problems. If you survive long enough to find them, they will answer your questions with a series of riddles. Each wrong answer loses you an eye, or worse, depending on the problem you need solving. Those who die by the witches become their ghostly slaves.
Red: crazy huge desert. At the center lie labyrinth filled upside-down pyramids. Those who don't go mad in the dessert will likely be kicked out by the minotaurs. Mountains are cubic and unnatural and lie at the edges of the desert. Home to goblins and mad nomads who beleive that only in true insanity can you find the ultimate question. Red asks riddles that can never be answered, as a catalyst for madness for them and others.
Green: forests grow in huge perfect cubes, and all connect to each other. Trees bend and stretch in a 3d labyrinth, akin to those plastic puzzle cubes with little steel marbles. This is perhaps one of the most peaceful places in the multiverse. The bright sun shines through beautifully through the trees, although once inside there are only two ways out. The only danger here are tiny talking insects, whispering wrong directions in your ears. But don't fret, the mostly flightless birds that reside here always face the way you need to go, or sing off in the distance so you can follow. During the night centaurs trim and prune the trees to keep them perfect and to create new paths. Never sleep in the forests, the maze changes each night. Everyone who visits the maze believes something amazing lies at its center, but all leave realizing that it would never answer the problems they came to solve.
Artificers live everywhere. Writing riddles and questions into thin metal scrolls, then melting them into shape. Everything they create turns into wondeful puzzles with a look of filligree.
Inhabitants of the plane are very diverse. Humans, vedalken, Merfolk, surrakar, cephalids, all manner of cephalapods, goblins, minotaurs, cats like felidar sovereign that act as our sphinxes (sphinxes can't stand a plane where everyone else is asking questions and not giving them answers), centaurs, birds, insects, all manner of small beasts. Any creature who's parents are a riddle, such as Pegasus, platypus, pheldagriffs and etc.
For linking a card to Gatherer without writting the name of said card for readers, use the autocard brackets together with and equal sign and right the name of the real card. Then put the message you want inside the tags, like you would do with autocarding. Like this:
I like storm crow because I really like crows in real life, as an animal, and the card isn't terribly stupid, but packs a good deal of nostalgia and also a chunck of the game's history. So it's perhaps one of the cards I have most affection to, but not because "lol storm crow is bad hurr hurr durr".
Oh, it's a brilliant plan. You see, Bolas was travelling through shadowmoor, causing trouble, when he saw a Wickerbough Elder with its stylin' dead scarecrow hat. Now, Bolas being Bolas took the awesome hat and he put it on his head, but even with all his titanic powers of magic he couldn't make it fit. He grabbed some more scarecrows, but then a little kithkin girl asked if he was trying to build a toupee. "BY ALL THE POWERS IN THE MULTIVERSE!" he roared, "I WILL HAVE A HAT WORTHY OF MY GLORY." and so he went through his Dark Lore of Doom (tm) looking for something he could make into a hat that would look as stylish on him as a scarecrow does on a treefolk. He thought about the Phyrexians, but they were covered in goopy oil that would make his nonexistant hair greasy. He Tried out angels for a while but they didn't sit quite right. Then, he looked under "e" (because in the Elder Draconic alphabet, "e" for Eldrazi is right next to "h" for Hat) in his Dark Lore of Doom and saw depictions of the Eldrazi, and all their forms. "THIS SHALL BE MY HAT!" he declared, poking a picture of Emrakul, "AND WITH IT I WILL USHER IN A NEW AGE OF DARKNESS -- ER, I MEAN A NEW AGE OF FASHION!"
And so Nicol Bolas masterminded the release of the Eldrazi.