Indighost, I think the wording works within the rules but I think the wording could be more clear. Could just be "Whenever equipped creature blocks or becomes blocked, it deals 1 damage to each creature blocking or blocked by it."
Mountaineer's Compass1
Artifact
When ~ enters the battlefield, put a +1/+1 counter on target creature you control. 1, T: Add one mana of any color.
Tale of Endless SummerG
Sorcery (C)
Add one mana of any color.
Draw a card.
Recount 2 - 1G(You may cast this spell for its recount cost. If you do, put it in your library second from the top instead of your graveyard)
Man this one probably requires a lot more thought than I'm going to give it to be honest.
The drawback feels very red. I think it really depends what your goals are. If the intent is to completely kill a self-mill strategy (assuming you succeed) I think this works fairly well at that - it would then remain interesting in an environment where you can find some other justification for it. If either the goal or the end result is that it's still worth it to put this in a self-mill deck, it would lead to a lot of no-fun games where the game is just a coin flip.
Normally I'd say that trying to make a drawback so severe that an otherwise broken card becomes "fair" is notoriously hard to make work, and there's usually a clever way around it. In this case I actually think it's possible that you could soften the drawback and it still wouldn't be out of this world broken. In order to OTK someone from 20, you have to mill about 35 cards which is a steep price. It might be more effective as efficient removal that can sometimes line up with other burn spells, but even then it's a pretty heavy investment and you never want to draw 2 of these.
This is probably a card that is impossible to balance without actual playtesting in specific environments, but after all of this rambling I think it's probably ok for it just to deal damage to you equal to the number of cards in GY, and not exile them.
-- Lizard UmbraR
Enchantment - Aura (C)
Enchant creature
Totem Armor (If enchanted permanent would be destroyed, instead remove all damage marked on it and destroy this Aura.)
Enchanted creature has haste.
Catch UpR
Enchantment (R)
Whenever a creature enters the battlefield under your control, if it's not the first creature to enter the battlefield this turn, it gains haste until end of turn.
Aven Ascetic3U
Creature - Bird Wizard (U)
When ~ enters the battlefield, draw 2 cards.
If you have 7 or more cards in your hand ~ gets +3/+3 and has flying.
1/1
netn10, Flatline (although it seems pretty broken)
Mind WandererUG
Creature - Human Wizard (M)
When ~ enters the battlefield, exile the top four cards of your library. T, Put a card exiled with ~ into your graveyard: Add one mana of any of that card's colors. G, T: Put a land card exiled with ~ onto the battlefield tapped. U: Return ~ to it's owner's hand.
0/2
Sifa Grent2(B/R)(B/R)
Planeswalker - Sifa
+2: Sifa Grent deals 2 damage to each opponent.
-1: Each opponent sacrifices a permanent.
-5: Create a 5/5 red and black Demon creature token with menace, haste and “This creature attacks each turn if able.”
3
Boundless Ephemeron4UU
Creature - Illusion (U)
When ~ enters the battlefield, draw a card. U: Exile. Return it to the battlefield at the beginning of the next end step.
3/4
Indighost, I think the wording works within the rules but I think the wording could be more clear. Could just be "Whenever equipped creature blocks or becomes blocked, it deals 1 damage to each creature blocking or blocked by it."
Mountaineer's Compass 1
Artifact
When ~ enters the battlefield, put a +1/+1 counter on target creature you control.
1, T: Add one mana of any color.
Tale of Endless Summer G
Sorcery (C)
Add one mana of any color.
Draw a card.
Recount 2 - 1G (You may cast this spell for its recount cost. If you do, put it in your library second from the top instead of your graveyard)
The drawback feels very red. I think it really depends what your goals are. If the intent is to completely kill a self-mill strategy (assuming you succeed) I think this works fairly well at that - it would then remain interesting in an environment where you can find some other justification for it. If either the goal or the end result is that it's still worth it to put this in a self-mill deck, it would lead to a lot of no-fun games where the game is just a coin flip.
Normally I'd say that trying to make a drawback so severe that an otherwise broken card becomes "fair" is notoriously hard to make work, and there's usually a clever way around it. In this case I actually think it's possible that you could soften the drawback and it still wouldn't be out of this world broken. In order to OTK someone from 20, you have to mill about 35 cards which is a steep price. It might be more effective as efficient removal that can sometimes line up with other burn spells, but even then it's a pretty heavy investment and you never want to draw 2 of these.
This is probably a card that is impossible to balance without actual playtesting in specific environments, but after all of this rambling I think it's probably ok for it just to deal damage to you equal to the number of cards in GY, and not exile them.
--
Lizard Umbra R
Enchantment - Aura (C)
Enchant creature
Totem Armor (If enchanted permanent would be destroyed, instead remove all damage marked on it and destroy this Aura.)
Enchanted creature has haste.
Grave Fate 1B
Instant (U)
As an additional cost to cast ~, exile target creature card from your graveyard.
Destroy target creature.
Tezzeret's Gift 2
Artifact (C)
Sacrifice ~: Add one mana of any color. Draw a card.
Zephymoeba 1U
Creature - Beast (U)
Discard a card: ~ gains hexproof until end of turn.
2/2
Catch Up R
Enchantment (R)
Whenever a creature enters the battlefield under your control, if it's not the first creature to enter the battlefield this turn, it gains haste until end of turn.
Tomb Unsealing XBB
Enchantment (U)
When ~ enters the battlefield, Amass X.
Exalted
Jace's Teachings 1UU
Enchantment - Aura (R)
Enchant Planeswalker
Enchanted Planeswalker has "+2: Return up to one target creature to its owner's hand.
Aven Ascetic 3U
Creature - Bird Wizard (U)
When ~ enters the battlefield, draw 2 cards.
If you have 7 or more cards in your hand ~ gets +3/+3 and has flying.
1/1
Viral Growth 2G
Sorcery (U)
Search your library for a basic land card and put it onto the battlefield tapped. Then shuffle your library.
Proliferate
Mind Wanderer UG
Creature - Human Wizard (M)
When ~ enters the battlefield, exile the top four cards of your library.
T, Put a card exiled with ~ into your graveyard: Add one mana of any of that card's colors.
G, T: Put a land card exiled with ~ onto the battlefield tapped.
U: Return ~ to it's owner's hand.
0/2
Static Elemental 1RR
Creature - Elemental (U)
Flash
When ~ ETB, it deals 1 damage to each creature.
2/2
Sifa Grent 2(B/R)(B/R)
Planeswalker - Sifa
+2: Sifa Grent deals 2 damage to each opponent.
-1: Each opponent sacrifices a permanent.
-5: Create a 5/5 red and black Demon creature token with menace, haste and “This creature attacks each turn if able.”
3
Boundless Ephemeron 4UU
Creature - Illusion (U)
When ~ enters the battlefield, draw a card.
U: Exile. Return it to the battlefield at the beginning of the next end step.
3/4