The blue in Exobotanical Gardens comes from the ETB Mana Severance. That general effect is still in Blue's color pie, at least as of Worldwake. (Selective Memory) Being able to then play those land cards exiled with the enchantment is where the Green factors in. Playing from exile is ill-defined, I agree, but I see no reason why this specific space could not be Green.
As to Vesuvian Mindbender - I like that effect at that cost. Probably would have been given an extra 2 if printed, but that would drop it from "neat" to "not worth it". That said, I'd change the creature control effect. Make it more like Banishing Light, i.e. until Vesuvan Mindbender leaves the battlefield.
Edit: oh man I love All the First. I have no concrit, I just want to say that i love it!
Vicious Mold3GGG
Creature - Plant Ooze (r)
Hexproof
At the beginning of each player's upkeep, that player sacrifices a noncreature, nonland permanent he or she controls. If that player does, put a +1/+1 counter on Vicious Mold.
2/1
Would lower the mana cost a bit and raise the p/t some. Also, I think the "he or she controls" clause is redundant. Players can't sacrifice permanents they don't control, I think. (They can make others sacrifice their permanents, of course.)
Devouring InfernoRR
Instant (r)
Devouring Inferno deals one damage to every creature on the battlefield.
If at least one creature was put into a graveyard due to Devouring Inferno, you may cast a copy of Devouring Inferno without paying its mana cost.
Oh gosh I love that effect. Very Goblin Sharpshooter! I'd add 1 to the casting cost though.
Let's see... Oh I know!
Exobotanical Gardens 3GU
Enchantment
When Exobotanical Gardens enters the battlefield, search your library for any number of land cards and exile them. Then shuffle your library.
You may play land cards exiled with Exobotanical Gardens.
This giant growth variant is pretty good, but if the set it is printed on has more ways of giving a creature "spore counters" it can very easily be overpowered. Also, if there are other spells that do things with "spore counters" (like give trample or something) this can easily be overpowered because you are not only growing your dude but also giving him some other ability for a measly G. Very context dependent.
Hmm, maybe. 2 spore counters for G feels right, but I could maybe swing 3 counters for 1G.
+1: Detain up to one target creature.
-4: Until your next turn, for each creature that attacks you or a planeswalker you control, chose one: gain two life or draw a card.
-10: You get an emblem with "whenever you draw a card, gain one life" and "2: shuffle your graveyard into your library, then draw five cards. Use this ability only once per turn."
Loyalty: 6
EDIT: fixed the emblem with "use only once per turn" to avoid infinite loops. Also, corrected the ultimate to -9 to make it a bit quicker. It is still a T9 ultimate at best, so I think this way it's well balanced, avoiding control matchups extending too long.
Hmm, it sorta works and that ultimate is very fair. I don't know, though. The effects feel disjointed and don't really seem like they'd mesh.
Oh gosh I like the names of the previous two cards and their effects. I think Extermination's cost is precisely right but I'm a bit uncertain re: Momentary Indecision's. I'm not sure it's enough bang for that, but it can only really be UR
Will edit post with a card shortly.
Ah right, here's one.
Giant Growth variant that doesn't bore me G
Instant (U)
Target creature gets 2 spore counters. It gains "This creature gets +1/+1 for each spore counter on it." until the beginning of the next end step.
Distortion Field1UR Instant
You and permanents you control gain hexproof until end of turn.
Whenever a spell an opponent controls is countered this turn, Distortion Field deals 2 damage to that player.
The first effect looks very Green/White, not really much like Blue. The second one is very Red, of course. Hmm.
I think this breaks complexity, but I coudl also see it doing 4 damage to big creatures.
Nissa, Broken3BG
Planeswalker - Nissa (MR - timeshifted)
{0}: Discard a card. If that card is a land card, put it onto the battlefield, then put 2 loyalty counters on Nissa, Broken.
{-2}: Put a 1/1 green and black Elf token onto the battlefield for each land you control.
{-7}: Destroy all lands. You lose life equal to the number of lands destroyed this way.
{7}
Should the first one maybe be a random discard? It's pretty okay overall, but I'm not feeling this card as a direction Nissa could go in, even "Broken".
Rummaging Dude 3G
Creature - Human Ranger
Delve
When Rummaging Dude ETB, draw a card.
2/2
I like Enhance, seriously digging it. I misread the card initially, thinking it put the lands onto the battlefield rather than into the hand and thought the effect slightly undercost for it but it's definitely right at that cost for that effect.
This has no name because I've no idea what I'd call it.
__ - XWBR
Sorcery
Each player reveals the top X cards of their library. You put all creature cards with converted mana 2 or less onto the battlefield under your control then put all other cards revealed into their owners' graveyards. 08:48 TIASIAN Those creatures gain haste. Sacrifice them at the beginning of the next end step.
I think the story for a Mono-Black planeswalker would have to take on a different structure than what most MTG stories normally use. Structure may not be e right word here, but I feel that for a story about a heroic Black-aligned planeswalker to work, it can't just be multiplanar jaunts.
Because modern morality is bull*****, if you don't kill the little black girl who's bringing down armageddon because that's ageist, racist, sexist and mean. YOU are evil! Because you allowed your ego to stop you from saving the world and every innocent life in it.
You're of the sort to complain about tumblr and SJWs, aren't you?
As far as the setting, I think they stick too closely to the volcanic theme for U/R lands. My favorite U/R land setting is Shivan Reef, which I have always felt was a more encompassing setting for such a dual land. I would have been happier with a name like "Seaboard Cliffs" or "Lithic Shoreline." Vulcanism is played out a bit in my opinon.
I looked up the UR lands on Gatherer... and yeah, there's a certain "pools of water near volcanoes" thing, but it's not quite as bad as the (more recent) B/G lands. Three - Overgrown Tomb, Verdant Catacomb, and now Woodland Cemetery all being the same thing haha
As to Vesuvian Mindbender - I like that effect at that cost. Probably would have been given an extra 2 if printed, but that would drop it from "neat" to "not worth it". That said, I'd change the creature control effect. Make it more like Banishing Light, i.e. until Vesuvan Mindbender leaves the battlefield.
Edit: oh man I love All the First. I have no concrit, I just want to say that i love it!
Would lower the mana cost a bit and raise the p/t some. Also, I think the "he or she controls" clause is redundant. Players can't sacrifice permanents they don't control, I think. (They can make others sacrifice their permanents, of course.)
Oh gosh I love that effect. Very Goblin Sharpshooter! I'd add 1 to the casting cost though.
Let's see... Oh I know!
Exobotanical Gardens 3GU
Enchantment
When Exobotanical Gardens enters the battlefield, search your library for any number of land cards and exile them. Then shuffle your library.
You may play land cards exiled with Exobotanical Gardens.
Hmm, maybe. 2 spore counters for G feels right, but I could maybe swing 3 counters for 1G.
Hmm, it sorta works and that ultimate is very fair. I don't know, though. The effects feel disjointed and don't really seem like they'd mesh.
Will edit post with a card shortly.
Ah right, here's one.
Giant Growth variant that doesn't bore me G
Instant (U)
Target creature gets 2 spore counters. It gains "This creature gets +1/+1 for each spore counter on it." until the beginning of the next end step.
The first effect looks very Green/White, not really much like Blue. The second one is very Red, of course. Hmm.
Should the first one maybe be a random discard? It's pretty okay overall, but I'm not feeling this card as a direction Nissa could go in, even "Broken".
Rummaging Dude 3G
Creature - Human Ranger
Delve
When Rummaging Dude ETB, draw a card.
2/2
So, where's the Blue in that? Seems fine just Black, tbh. Could also maybe make it 2 instead of B. Seems more reasonable that way.
Nasty Buggy 3
Creature - Insect
Delve, Dredge 3
Deathtouch
1/3
Maybe? I just felt like going as BG as I could, haha. Edit: whoops left out details. Maybe call it Dastardly d-something to go with those keywords.
This has no name because I've no idea what I'd call it.
__ - XWBR
Sorcery
Each player reveals the top X cards of their library. You put all creature cards with converted mana 2 or less onto the battlefield under your control then put all other cards revealed into their owners' graveyards. 08:48 TIASIAN Those creatures gain haste. Sacrifice them at the beginning of the next end step.
I could probably use some templating help. Hmm.
You're of the sort to complain about tumblr and SJWs, aren't you?
It's creatures that are boring.
Let's have lands that do things!
edit: this excludes man-lands btw. Bo-ring. We've already got dozens of them out there.
Grim Lavamancer, mayhap?
I looked up the UR lands on Gatherer... and yeah, there's a certain "pools of water near volcanoes" thing, but it's not quite as bad as the (more recent) B/G lands. Three - Overgrown Tomb, Verdant Catacomb, and now Woodland Cemetery all being the same thing haha
The flavortext of Lost Leonin, Loxodon Convert, and Phyrexia's Core are all rather poignant.