I don't think this "fix"es anything, if we're using a definition of "fix" that means "solve the problems of the status quo and fail to introduce worse problems."
Seven-Seas Conch7
Legendary Artifact
Sacrifice Seven-Seas Conch: You may pay 0 rather than pay the mana cost of the next seven spells you cast this turn.
I don't really think these need the "as long as modified artifact is a creature" verbiage since the vast majority of them are meaningless when that statement isn't true. It just wastes space on a textbox that's already going to be crowded by the modify text and "Modified artifact has, ""
Learned General becomes Esteemed Tactician: Esteemed Tactician
Creature — Human Advisor (U)
Whenever Esteemed Tactician attacks, choose up to one target creature an opponent controls. You choose how that creature blocks this turn.
2/2
Minister of Lies scry ability changed to menace
South Lake Oracle becomes Yunhai Shaman: Yunhai Shaman
Creature — Human Shaman (U)
Whenever you put a +1/+1 counter on a creature you control, target opponent loses 1 life and you gain 1 life. : Potential 2. (If this permanent has fewer than two +1/+1 counters on it, put a +1/+1 counter on it.)
2/2
Blazing Messenger3WW
Creature — Angel (M)
Miracle 2RW
Flying, hexproof
When you cast Blazing Messenger for its miracle cost, it gains haste until end of turn. You may return an Aura from your graveyard to the battlefield attached to it.
5/5
Digging for a land sounds right. I'll see how that looks on the card!
I'll also take your advice on that wording change on the Bixi.
Learned General - Was not-great to start, now it's too similar to Bixi, so something has to give way. I'll be putting some thought into that before I have an answer for it, though.
Minister of Lies - I love the idea of making this evasive instead of having a triggered scry.
South Lake Oracle - Another one that needs replacement; it's maybe too similar to Viperskull right now.
Thanks for the feedback! As it turns out, I spotted two of the problem cards and cut them: Dragon Guide and Lieutenant of the Scale, and replaced them with:
Light of Autumn1RG
Sorcery
Scry 1, then reveal the top card of your library. If it’s a land card, put it onto the battlefield tapped.
Whenever a creature you control attacks this turn, it gets +1/+1 until end of turn.
Hard-Shelled Bixi2RU
Creature — Turtle Dragon
Whenever a Dragon you control attacks, you may have Hard-Shelled Bixi deal 2 damage to any target and 2 damage to target creature you control.
2/4
The version of shifty that doesn't last until end of turn is effectively just a power modifier, so it's absolutely necessary to have the swap last ueot.
Infernal Cadaver2B
Creature — Zombie (C)
Infernal Cadaver enters the battlefield tapped.
As long as you control a Demon, Infernal Cadaver has indestructible.
2/2
Tasigur, Khan of Fangs1BGU
Legendary Creature — Human Shaman (M)
Wealth (When this creature dies, reveal the top card of your library. If it has a lower converted mana cost than this card, put it into your hand.)
Whenever a creature you control dies, scry 1.
3/4
Legendary Artifact
Sacrifice Seven-Seas Conch: You may pay 0 rather than pay the mana cost of the next seven spells you cast this turn.
Learned General becomes Esteemed Tactician:
Esteemed Tactician
Creature — Human Advisor (U)
Whenever Esteemed Tactician attacks, choose up to one target creature an opponent controls. You choose how that creature blocks this turn.
2/2
Minister of Lies scry ability changed to menace
South Lake Oracle becomes Yunhai Shaman:
Yunhai Shaman
Creature — Human Shaman (U)
Whenever you put a +1/+1 counter on a creature you control, target opponent loses 1 life and you gain 1 life.
2/2
Creature — Angel (M)
Miracle 2RW
Flying, hexproof
When you cast Blazing Messenger for its miracle cost, it gains haste until end of turn. You may return an Aura from your graveyard to the battlefield attached to it.
5/5
I'll also take your advice on that wording change on the Bixi.
Learned General - Was not-great to start, now it's too similar to Bixi, so something has to give way. I'll be putting some thought into that before I have an answer for it, though.
Minister of Lies - I love the idea of making this evasive instead of having a triggered scry.
South Lake Oracle - Another one that needs replacement; it's maybe too similar to Viperskull right now.
Light of Autumn 1RG
Sorcery
Scry 1, then reveal the top card of your library. If it’s a land card, put it onto the battlefield tapped.
Whenever a creature you control attacks this turn, it gets +1/+1 until end of turn.
Hard-Shelled Bixi 2RU
Creature — Turtle Dragon
Whenever a Dragon you control attacks, you may have Hard-Shelled Bixi deal 2 damage to any target and 2 damage to target creature you control.
2/4
Legend: Good play. I like that you made a land for this challenge.
RaikouRider: You all really seem to think that there's going to be 11 mana just like on the table at some point.
netn10: Smart move including a cost reduction effect here.
Subject16: I find it suspect that you're going to have 11 mana lying around in most formats.
TheDrB: By the time you can cast this, I feel like it's unlikely that most opponents will have very much in hand.
Top 3:
1. Legend
2. netn10
3. Cardz5000
Raptorchan: Unexciting but okay.
zdtsd: This is pretty absurd for coin-flip decks.
Gateways7: Funny, ok.
Artorias: Okay, this is very reminishent of Norin but it works.
Algernone25: The tribal solution, eh. I find that a bit unsatisfying.
Top 3:
1. Gateways7
2. Raptorchan
3. Artorias
Legendary Land — Gate (M)
When The Final Gate enters the battlefield, untap all lands you control.
T: Add C.
Creature — Zombie (C)
Infernal Cadaver enters the battlefield tapped.
As long as you control a Demon, Infernal Cadaver has indestructible.
2/2
Legendary Creature — Human Shaman (M)
Wealth (When this creature dies, reveal the top card of your library. If it has a lower converted mana cost than this card, put it into your hand.)
Whenever a creature you control dies, scry 1.
3/4