I'm a fan of the leylines, but I always felt like they should have been costed more aggressively because they honestly suck when they aren't in your opening hand.
So here's a new cycle with cheaper casting costs:
Leyline of Oblivion2W
Enchantment
If Leyline of Oblivion is in your opening hand, you may begin the game with it on the battlefield.
If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.
As long as they keep printing things like Arclight Phoenix, more effects like this are always welcome as a counterbalancing measure
Leyline of Winter2U
Enchantment
If Leyline of Winter is in your opening hand, you may begin the game with it on the battlefield.
Permanents enter the battlefield tapped.
This one I designed to capture to flavor of winter slowing everything down
Leyline of Shadows2B
Enchantment
If Leyline of Shadows is in your opening hand, you may begin the game with it on the battlefield.
At the beginning of each player's upkeep, that player discards a card.
This one could make for some non-games but putting players in topdeck mode too quickly, but I'd love to see a Madness deck take advantage of this effect.
Leyline of Explosives2R
Enchantment
If Leyline of Explosives is in your opening hand, you may begin the game with it on the battlefield.
Whenever a player casts a spell, Leyline of Explosives deals damage to that player equal to the number of spells that player cast this turn.
Storm/combo hoser but is also fine against any deck because it still deals a guaranteed 1 damage per spell.
Leyline of Abundance2G
Enchantment
If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever a player taps a land for mana, that player adds one mana of any color that land could produce to their mana pool.
Potentially very powerful mana acceleration, but as it affects all players I think this should be ok.
Leyline of oblivion is way too good. it does what leyline of the void currently does (ie anti-reanimator), costs less (therefore actually castable) and also hits tinker, show and tell, aether vial. etc.
Leyline of shadows -- Too undercosted as it is, then make it a leyline? Whoohoo, I play multiple copies on turn 1!
Leyline of explosives -- cute, but storm will bounce this before going off, like every other permanent storm hoser. This is worse, since storm hosers usually are capanble of defending themselves (ie cotv, spheres) by making the bounce spell harder to cast. Still kinda usable.
I think you underestimate some of this effects particularly when a deck is build around them. Leyline of Abundance for example gives a turn 1 mana ramp spell (Farseek, Rampant Growth, etc) into turn 2 six mana spell say Primeval Titan or just more ramp into 10 drops on turn 3.
Leyline of Shadows and Leyline of Abundance are busted.
T1: Leyline, Summer Bloom, 6-drop
T2: Oh, you're still here?
Meanwhile Leyline of Shadows gets jammed into every reanimator or dredge deck ever.
Leyline of Oblivion isn't strictly better than Leyline of the Void, or even close (doesn't stop flashback, Snapcaster, Jace's GY count, etc.) so I think it's probably fine.
Leyline of Winter is, ironically, best in fast and aggressive decks, since it means creatures can't block the turn they hit play but they can attack the turn after just fine. I do like it just as a way to punish fetches though. (the fetch enters tapped, then the land it fetches also enters tapped)
So here's a new cycle with cheaper casting costs:
Leyline of Oblivion 2W
Enchantment
If Leyline of Oblivion is in your opening hand, you may begin the game with it on the battlefield.
If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.
As long as they keep printing things like Arclight Phoenix, more effects like this are always welcome as a counterbalancing measure
Leyline of Winter 2U
Enchantment
If Leyline of Winter is in your opening hand, you may begin the game with it on the battlefield.
Permanents enter the battlefield tapped.
This one I designed to capture to flavor of winter slowing everything down
Leyline of Shadows 2B
Enchantment
If Leyline of Shadows is in your opening hand, you may begin the game with it on the battlefield.
At the beginning of each player's upkeep, that player discards a card.
This one could make for some non-games but putting players in topdeck mode too quickly, but I'd love to see a Madness deck take advantage of this effect.
Leyline of Explosives 2R
Enchantment
If Leyline of Explosives is in your opening hand, you may begin the game with it on the battlefield.
Whenever a player casts a spell, Leyline of Explosives deals damage to that player equal to the number of spells that player cast this turn.
Storm/combo hoser but is also fine against any deck because it still deals a guaranteed 1 damage per spell.
Leyline of Abundance 2G
Enchantment
If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever a player taps a land for mana, that player adds one mana of any color that land could produce to their mana pool.
Potentially very powerful mana acceleration, but as it affects all players I think this should be ok.
Hands to the sky
Give a round of applause
For the great Miss Y!
Leyline of shadows -- Too undercosted as it is, then make it a leyline? Whoohoo, I play multiple copies on turn 1!
Leyline of explosives -- cute, but storm will bounce this before going off, like every other permanent storm hoser. This is worse, since storm hosers usually are capanble of defending themselves (ie cotv, spheres) by making the bounce spell harder to cast. Still kinda usable.
"Sometimes, the situation is outracing a threat, sometimes it's ignoring it, and sometimes it involves sideboarding in 4x Hope//Pray." --Doug Linn
T1: Leyline, Summer Bloom, 6-drop
T2: Oh, you're still here?
Meanwhile Leyline of Shadows gets jammed into every reanimator or dredge deck ever.
Leyline of Oblivion isn't strictly better than Leyline of the Void, or even close (doesn't stop flashback, Snapcaster, Jace's GY count, etc.) so I think it's probably fine.
Leyline of Winter is, ironically, best in fast and aggressive decks, since it means creatures can't block the turn they hit play but they can attack the turn after just fine. I do like it just as a way to punish fetches though. (the fetch enters tapped, then the land it fetches also enters tapped)
- Rabid Wombat
The other two are far beyond the pale.
I̟̥͍̠ͅn̩͉̣͍̬͚ͅ ̬̬͖t̯̹̞̺͖͓̯̤h̘͍̬e͙̯͈̖̼̮ ̭̬f̺̲̲̪i͙͉̟̩̰r̪̝͚͈̝̥͍̝̲s̼̻͇̘̳͔ͅt̲̺̳̗̜̪̙ ̳̺̥̻͚̗ͅm̜̜̟̰͈͓͎͇o̝̖̮̝͇m̯̻̞̼̫̗͓̤e̩̯̬̮̩n͎̱̪̲̹͖t͇̖s̰̮ͅ,̤̲͙̻̭̻̯̹̰ ̖t̫̙̺̯͖͚̯ͅh͙̯̦̳̗̰̟e͖̪͉̼̯ ̪͕g̞̣͔a̗̦t̬̬͓͙̫̖̭̻e̩̻̯ ̜̖̦̖̤̭͙̬t̞̹̥̪͎͉ͅo͕͚͍͇̲͇͓̺ ̭̬͙͈̣̻t͈͍͙͓̫̖͙̩h̪̬̖̙e̗͈ ̗̬̟̞̺̤͉̯ͅa̦̯͚̙̜̮f͉͙̲̣̞̼t̪̤̞̣͚e̲͉̳̥r͇̪̙͚͓l̥̞̞͎̹̯̹ͅi͓̬f̮̥̬̞͈ͅe͎ ̟̩̤̳̠̯̩̯o̮̘̲p̟͚̣̞͉͓e͍̩̣n͔̼͕͚̜e̬̱d̼̘͎̖̹͍̮̠,͖̺̭̱̮ ̣̲͖̬̪̭̥a̪͚n̟̲̝̤̤̞̗d̘̱̗͇̮͕̳͕͔ ͖̞͉͎t̹̙͎h̰̱͉̗e̪̞̱̝̹̩ͅ ̠̱̩̭̦p̯̙e͓o̳͚̰̯̺̱̰͔̘p̬͎̱̣̼̩͇l̗̟̖͚̠e̱͉͔̱̦̬̟̙ ̖͚̪͔̼̦w̺̖̤̱e͖̗̻̦͓̖̘̜r̭̥e͔̹̫̱͕̦̰͕ ̗͔̠p̠̗͍͍̱̳̠r̰͔͎̰o͉̥͓̰͚̥s̟͚̹̱͔̣t͉̙̳̖͖̪̮r̥̘̥͙̹a͉̟̫̟̳̠̟̭t͈̜̰͈͎e̞̣̭̲̬ ͚̗̯̟͙i͍͖̰̘̦͖͉ṇ̮̻̯̦̲̩͍ ̦̮͚̫̤t͉͖̫͕ͅͅh͙̮̻̘̣̮̼e͕̺ ͙l͕̠͎̰̥i̲͓͉̲g̫̳̟͈͇̖h̠̦̖t͓̯͎̗ ̳̪̘̟̙̩̦o̫̲f̙͔̰̙̠ ̹̪̗͇̯t͖̼̼͉͖̬h̹͇̩e͚̖̺̤͉̹͕̪ ͚͓̭̝̺G͎̗̯̩o̫̯̮̟̮̳̘d̜̲͙̠-̩̳̯̲̗̜P̹̘̥͉̝h͍͈̗̖̝ͅa͍̗̮̼̗r̜̖͇̙̺a̭̺͔̞̳͈o̪̣͓̯̬͙̯̰̗h̖̦͈̥̯͔.͇̣̙̝