I recently had this crazy idea for these lands based on the Zendikar etb lands and others such as Crumbling Vestige.
Waterway Tract
Land (U)
Waterway Tract enters the battlefield tapped.
When Waterway Tract enters the battlefield, add W to your mana pool.
: Add U to your mana pool.
Subterranean Oasis
Land (U)
Subterranean Oasis enters the battlefield tapped.
When Subterranean Oasis enters the battlefield, add U to your mana pool.
: Add B to your mana pool.
Molten Bog
Land (U)
Molten Bog enters the battlefield tapped.
When Molten Bog enters the battlefield, add B to your mana pool.
: Add R to your mana pool.
Crag Thicket
Land (U)
Crag Thicket enters the battlefield tapped.
When Crag Thicket enters the battlefield, add R to your mana pool.
: Add G to your mana pool.
Hallowedtimber Meadow
Land (U)
Hallowedtimber Meadow enters the battlefield tapped.
When Hallowedtimber Meadow enters the battlefield, add G to your mana pool.
: Add W to your mana pool.
Now this cycle is just the main allied color combinations. I also could expand on this design and make the enemy color combinations, as well as the reverse allied and enemy colors for a total of 20 lands.
Questions, comments, concerns, constructive criticisms, conundrums?
Waterway Tract
Land (U)
Waterway Tract enters the battlefield tapped.
When Waterway Tract enters the battlefield, add W to your mana pool.
: Add U to your mana pool.
Subterranean Oasis
Land (U)
Subterranean Oasis enters the battlefield tapped.
When Subterranean Oasis enters the battlefield, add U to your mana pool.
: Add B to your mana pool.
Molten Bog
Land (U)
Molten Bog enters the battlefield tapped.
When Molten Bog enters the battlefield, add B to your mana pool.
: Add R to your mana pool.
Crag Thicket
Land (U)
Crag Thicket enters the battlefield tapped.
When Crag Thicket enters the battlefield, add R to your mana pool.
: Add G to your mana pool.
Hallowedtimber Meadow
Land (U)
Hallowedtimber Meadow enters the battlefield tapped.
When Hallowedtimber Meadow enters the battlefield, add G to your mana pool.
: Add W to your mana pool.
Now this cycle is just the main allied color combinations. I also could expand on this design and make the enemy color combinations, as well as the reverse allied and enemy colors for a total of 20 lands.
Questions, comments, concerns, constructive criticisms, conundrums?
Servien
Chaos' Realm
Escalation of Chaos
Tales of Cahdaria
Enigmatic Distrubance
Celestial Unveiling
I̟̥͍̠ͅn̩͉̣͍̬͚ͅ ̬̬͖t̯̹̞̺͖͓̯̤h̘͍̬e͙̯͈̖̼̮ ̭̬f̺̲̲̪i͙͉̟̩̰r̪̝͚͈̝̥͍̝̲s̼̻͇̘̳͔ͅt̲̺̳̗̜̪̙ ̳̺̥̻͚̗ͅm̜̜̟̰͈͓͎͇o̝̖̮̝͇m̯̻̞̼̫̗͓̤e̩̯̬̮̩n͎̱̪̲̹͖t͇̖s̰̮ͅ,̤̲͙̻̭̻̯̹̰ ̖t̫̙̺̯͖͚̯ͅh͙̯̦̳̗̰̟e͖̪͉̼̯ ̪͕g̞̣͔a̗̦t̬̬͓͙̫̖̭̻e̩̻̯ ̜̖̦̖̤̭͙̬t̞̹̥̪͎͉ͅo͕͚͍͇̲͇͓̺ ̭̬͙͈̣̻t͈͍͙͓̫̖͙̩h̪̬̖̙e̗͈ ̗̬̟̞̺̤͉̯ͅa̦̯͚̙̜̮f͉͙̲̣̞̼t̪̤̞̣͚e̲͉̳̥r͇̪̙͚͓l̥̞̞͎̹̯̹ͅi͓̬f̮̥̬̞͈ͅe͎ ̟̩̤̳̠̯̩̯o̮̘̲p̟͚̣̞͉͓e͍̩̣n͔̼͕͚̜e̬̱d̼̘͎̖̹͍̮̠,͖̺̭̱̮ ̣̲͖̬̪̭̥a̪͚n̟̲̝̤̤̞̗d̘̱̗͇̮͕̳͕͔ ͖̞͉͎t̹̙͎h̰̱͉̗e̪̞̱̝̹̩ͅ ̠̱̩̭̦p̯̙e͓o̳͚̰̯̺̱̰͔̘p̬͎̱̣̼̩͇l̗̟̖͚̠e̱͉͔̱̦̬̟̙ ̖͚̪͔̼̦w̺̖̤̱e͖̗̻̦͓̖̘̜r̭̥e͔̹̫̱͕̦̰͕ ̗͔̠p̠̗͍͍̱̳̠r̰͔͎̰o͉̥͓̰͚̥s̟͚̹̱͔̣t͉̙̳̖͖̪̮r̥̘̥͙̹a͉̟̫̟̳̠̟̭t͈̜̰͈͎e̞̣̭̲̬ ͚̗̯̟͙i͍͖̰̘̦͖͉ṇ̮̻̯̦̲̩͍ ̦̮͚̫̤t͉͖̫͕ͅͅh͙̮̻̘̣̮̼e͕̺ ͙l͕̠͎̰̥i̲͓͉̲g̫̳̟͈͇̖h̠̦̖t͓̯͎̗ ̳̪̘̟̙̩̦o̫̲f̙͔̰̙̠ ̹̪̗͇̯t͖̼̼͉͖̬h̹͇̩e͚̖̺̤͉̹͕̪ ͚͓̭̝̺G͎̗̯̩o̫̯̮̟̮̳̘d̜̲͙̠-̩̳̯̲̗̜P̹̘̥͉̝h͍͈̗̖̝ͅa͍̗̮̼̗r̜̖͇̙̺a̭̺͔̞̳͈o̪̣͓̯̬͙̯̰̗h̖̦͈̥̯͔.͇̣̙̝