So... HERE WE GO!
1. Agido the Ancient Sentinel & Kelbek the Ancient Vanguard
Make them so you cannot Special Summon non-EARTH Fairy monsters when you use their effects so you can't splash them with Tearlaments which is the main reason why they both got banned in the first place.
2. Artifact Scythe
Replace:
If this card is Special Summoned during your opponent's turn: Your opponent cannot Special Summon monsters from the Extra Deck for the rest of this turn.
with:
Your opponent can only Special Summon monster(s) from their Extra Deck once per turn while you control this face-up card Special Summoned this turn.
That way, it'll still limit the opponent's ability to access the extra deck, but now, it at least gives them 1 special summon from it, and it also now allows them to get rid of this monster or negate its effect with something to open up the extra deck, whereas previously, even if you played a card like Raigeki to get rid of it, its effect would still linger for that turn due to how it was worded.
3. Barrier Statue of the Stormwinds
Make it only limit Special Summons from a certain area like the hand, Deck, or GY.
4. Blackwing - Gofu the Vague Shadow
Make it so you cannot Special Summon monsters from the Extra Deck the turn you use it's Token Summoning Effect except DARK Winged Beast and Dragon Synchro monsters.
5. Block Dragon
Make it so it or any copy of it can't special summon more than once per turn. Remove it's destruction protection effect. These would nerf it enough to still keep it powerful, but not letting you do crazy stuff like summoning it multiple times from the hand and graveyard to link summon during the opponent's turn with I:P Masquerena to generate even more unfair advantage.
7. Cyber-Stein
Make it's effect a soft once per turn and make it only able to activate it's effect if you have no Spells/Traps in your Spell/Trap Zone. This way, you cannot abuse it with Reprodocus and Telekinetic Charging Cell to perform OTKs.
8. Dandylion
Make it's effect a Hard once per turn and make it so that the tokens cannot be used as Link Material the turn they are Summoned.
9. Djinn Releaser of Rituals
Replace
the other player cannot Special Summon while that Ritual Summoned monster is face-up on the field.
with
the other player can only Special Summon once per turn while that Ritual Summoned monster is face-up on the field.
This way it will Limit "the other player" from Special Summoning and only if they Special Summon. Being able to Stop Special Summons anywhere is the main problem.
10. Eclipse Wyvern
Replace
1 Level 7 or higher LIGHT or DARK Dragon-Type monster
with
1 Level 7 Dragon monster
So you cannot search Chaos Dragon Levianeer and other good dragons above Level 7. A lot of people suggested it can only activate 1 of it's effects once per turn and only once that turn but this would end up breaking the card rendering it Unplayable.
11. Eva
Honestly, this card is Obviously Limited in the OCG and people aren't giving a damn in the OCG so it can come off with out a change. If it did, make it say "when" than "if" so it can miss it's Timing.
12. Fairy Tail - Snow
1 effect per turn, and only once that turn. Easy Change.
13. Fiber Jar
Like the other Jar monsters. I think this card can come off unchanged. If it did, just make it only shuffle cards from hand and field only.
14. Fishborg Blaster
Make it a Hard Once per turn.
15. Glow-Up Bulb
Now that Linkuriboh is banned, I think this card can come off the list fine. Otherwise, make it only activate it's effect outside of the turn it is sent there.
16. Grinder Golem
Make it (and any copy of it) only able to Special Summon itself once per turn.
17. Level Eater
Make it a Hard Once per turn.
18. Magical Scientist
Again, HOPT.
19. Master Peace, the True Dracoslaying King
Replace "Unaffected by the effects of cards with the same card type (Monster, Spell, and/or Trap) as the original card type of the cards Tributed for its Tribute Summon" with "Cannot be destroyed by the effects of cards with the same card type (Monster, Spell, and/or Trap) as the original card type of the cards Tributed for its Tribute Summon". This way, it will be imperveous from Destruction but it can be banished, bounced, etc. by other means.
20. Mathmech Circular
Make it only Search Spells/Traps outside of the turn it is summoned and make it so you cannot Special Summon non-Cyberse the turn you activate either of it's effects.
21. Maxx "C"
Change its effect from:
During either player's turn: You can send this card from your hand to the Graveyard; this turn, each time your opponent Special Summons a monster(s), immediately draw 1 card. You can only use 1 "Maxx "C"" per turn.
to:
(Quick Effect): You can send this card from your hand to the GY and declare 1 place (hand, Deck, Extra Deck, GY); this turn, you cannot activate other cards or effects, also each time your opponent Special Summons a monster(s) from that declared place of theirs, immediately draw 1 card. You can only use 1 "Maxx "C"" per turn.
22. Mind Master
Make it a Hard once per turn.
23. Performage Plushfire
Make it a Hard Once per turn on it's monster effect.
24. Phoenixian Cluster Amaryllis
Make it only able to activate it's effect to Revive itself up to 2 or 3 times per turn.
25. Ronintoadin
Make it so you cannot Special Summon non-Aqua monsters the turn you activate it's effects so you cannot abuse it in Sprights.
26. SPYRAL Master Plan
Make it only activate 1 effect per turn and only once that turn.
27. The Tyrant Neptune
Change " Target 1 Effect Monster in the Graveyard that was Tributed for the Tribute Summon; this card's name becomes that target's name, and this card gains that target's effects." to " Target 1 Effect Monster in the GY that can be Normal Summoned/Set that was Tributed for the Tribute Summon; this card's name becomes that target's name, and this card gains that target's effects.. This way, you cannot use it to copy Lyrilusc - Independent Nightingale
28. Victory Dragon
I know this kinda sounds stupid, so change the effect:
If this card attacks your opponent directly and reduces their Life Points to 0, you win the Match.
to
If this card inflict battle damage to your opponent by a direct attack, you win the Duel.
29. Elder Entity Norden
Make it's effect a Hard once per turn.
30. Supreme King Dragon Starving Venom
As I said before with The Tyrant Neptune (#27) make it only copy monsters that can be Normal Summoned/Set.
31. Tearlaments Kitakallos
Add the restriction:
You cannot Special Summon the turn you activate either of those effects, except "Tearlaments" monsters.
This way, you can't abuse it in other decks that rely on milling which is the reason why this card got banned.
32. Baronne de Fleur
Make it only negate monster effects to parallel Chevalier de Fleur. Some suggested it must be summoned with Fleur Synchron instead of any Tuner or require a non-Tuner Fusion or Synchro monster, but this kills the card's Purpose rendering it Unplayable.
33. Borreload Savage Dragon
Make it only summonable using a DARK Tuner and Dragon non-Tuners just like the Fusion and Xyz monsters and Make it only be able to Equip DARK Dragon Link monsters just like how it was used in the Anime to reduce Splashability.
34. Chaos Ruler, the Chaotic Magical Dragon
Make it so any cards milled off it's effect and any card that shares a name with the milled cards cannot activate their effects. This way, you cannot abuse it in Mill Based Decks.
35. Tempest Magician
Make it so it must remove spell counters from itself, not just anywhere on the field, to activate it's damaging effect.
36. Kashtira Arise-Heart
Make it only banish cards that are being sent from the field to the GY and it's Detach 3 effect not a Quick Effect.
37. Lavalval Chain
Make it dump and place Laval cards and monsters respectively instead of any card
38. M-X-Saber Invoker
Make it negate the Summoned monster's effects in a way similar to Rescue Cat
39. Number 16: Shock Master
Replace
that type of card (if Spell or Trap) cannot be activated, or (if Monster) cannot activate its effects, until the end of your opponent's next turn.
with
each player can only activate 1 card or effect of the declared type until the End Phase.
40. Number 42: Galaxy Tomahawk
Make it so you can only Special Summon from the Extra Deck once during the turn you activate it's effect.
41. Number 86: Heroic Champion - Rhongomyniad
Replace
● 4+: Your opponent cannot Normal or Special Summon monsters.
with
● 4+: Your opponent cannot Special Summon more than 1 monster per turn.
This way, it will not leave your opponent helpless meaning they can still get rid of it with a Kaiju.
42. Number 89: Diablosis the Mind Hacker
Replace the effect:
If a card your opponent owns and possesses is banished face-down while you control this card (except during the Damage Step): You can banish cards from the top of your opponent's Deck, face-down, equal to their face-down banished cards.
with
If a card your opponent owns and possesses is banished face-down while you control this card (except during the Damage Step): You can banish the top card of your opponent's Deck face down.
43. Number 95: Galaxy-Eyes Dark Matter Dragon
Reduce the number of Dragon monsters it dumps to activate its effect from 3 to 2 or 1.
44. Number S0: Utopic Zexal
Make it's Quick Effect only last for a Phase than an Entire turn.
45. Outer Entity Azathot
Replace
After this card was Xyz Summoned, your opponent cannot activate monster effects for the rest of that turn.
with
After this card was Xyz Summoned, monsters your opponent currently controls cannot activate their effects this turn.
46. True King of All Calamities
Make it's effect not a Quick Effect and make it prevent monsters with the declared Original Attribute from activating effects
47. Wind-Up Carrier Zenmaity
Make it's effects a hard once per turn.
48. Zoodiac Broadbull
Make it so you cannot Normal Summon/Set, Special Summon, or activate the effects of the Searched monster (or any copy of it) the turn you activate it's effect and make it a hard once per turn.
50. Zoodiac Drident
This card went to Hell & Back, so no Errata what so ever. Otherwise, replace
target 1 face-up card on the field; destroy it.
with
target 1 monster on the field; destroy it.
Which makes it a Tornado Dragon, but for monsters
51. Crystron Halqlifibax
Add the restriction:
You cannot Special Summon from the Extra Deck the turn you activate either of it's effects, except WATER and Synchro monsters.
52. Curious, the Lightsworn Dominion
Honestly, we got new Lightsworn stuff from Legacy of Destruction so it doesn't need an errata at all. But, we could make it only dump Lightsworn cards than anything.
53. Guardragon Agarpain and Guardragon Elpy
Make it so the Summoned monster cannot declare an attack or activate it's effects the turn it is Summoned.
54. Heavymetalfoes Electrumite
Make it's effects a hard once per turn.
55. Isolde, Two Tales of the Noble Knights
Make it only use it's Summon effect outside the Turn it is Special Summoned and make it only search and Summon FIRE, LIGHT, and DARK Warrior monsters with it's effect so you can't summon any of the Gouki Monsters. The only Archetypes outside of Noble Knights that fall under the category would be Igknight, Destiny HERO, and tellarknights. A lot of people suggest it to only search and summon the Noble Knights or make 1 of the Link Materials a Noble Knight monster, but it doesn't work that way resulting in the card being unplayable.
56. Knightmare Goblin
Make it only prevent it's Fellow Knightmares from being targeted.
57. Knightmare Mermaid
Make it so you cannot Special Summon non-Knightmare monsters from the extra deck the turn you activate it's effect.
58. Linkross
Make it so you cannot Tribute the Link Tokens for a Tribute or Ritual Summon nor use them as Fusion, Synchro, or Link material instead of just Link Material.
59. Linkuriboh
Make it so you can only use it's Revival Effect outside of the turn it is sent there.
60. Mecha Phantom Beast Auroradon
Make it Link materials WIND Machine monsters instead of any Machine monster and it's effects a hard once per turn.
61. Prank-Kids Meow-Meow-Mu
This card can come off the list without one because Prank-Kids is one of those Mediocre Archetypes that sees play. if it did, make it only activate it's effects from the field or GY (and not the other way)
62. Predaplant Verte Anaconda
Make it's Materials DARK Plant monsters to reduce Splashability damn it.
63. Simorgh, Bird of Sovereignty
Make it only Summon a Level 6 or lower Winged Beast monster so you can't summon Dark Simorgh or Mist Valley Apex Avaian
64. Spright Elf
Make it only protect Level/Rank/Link 2 monsters it points to and cannot Special Summon non-Level/Rank/Link 2 monsters the turn you use it's effect.
Summon Sorceress is being skipped because it's getting an Errata for real but not until July!
65. Superheavy Samurai Scarecrow
Add a Restriction:
You cannot Special Summon the turn you activate this effect, except "Superheavy Samurai" monsters.
66. Topologic Gumblar Dragon
Make it only able to activate it's effects outside of the first turn of the Duel.
67. Union Carrier
Change the effect
You can target 1 face-up monster you control; equip 1 monster to it from your hand or Deck with its same original Type or Attribute. The equipped monster gains 1000 ATK. If you equipped it from the Deck, you cannot Special Summon monsters with that Equip Card's name for the rest of this turn.
to
You can target 1 face-up monster you control; equip 1 Level 2 or higher monster to it from your hand or Deck with its same original Type or Attribute. The equipped monster gains 1000 ATK. Also, you cannot Special Summon from the Spell/Trap Zone nor inflict damage for the rest of this turn.
This way, you cannot abuse it with Dragon Buster Destruction Sword. Many people suggested it to only Equip Union Monsters, but this change makes the card completely Unplayable.
68. Brilliant Fusion
Make it so the Gem-Knight you Fusion Summon has to be at least Level 7 or 8 or higher. So you cannot Summon Gem-Knight Seraphinite for a Boost in Summons or Gem-Knight Lady Lapis Lazuli to OTK your opponent
69
. Butterfly Dagger - Elma, Card of Safe Return
Hard Once, twice, or maybe thrice per turns...
70. Cold Wave
Make it so it only stops the opponent's Spells/Traps for the turn its activated instead of also the turn after that.
71. Confiscation, The Forceful Sentry
Make it only remove monsters with an effect that activates from the hand.
72. Dimension Fusion
Make it so the monsters cannot be Tributed nor be used as Fusion, Synchro, Xyz, and Link Material the turn they are summoned.
73. Deliquent Duo
Make it so the opponent must have at least 6 cards in their hand for you to activate this spell.
74. Giant Trunade
This card felt like getting unbanned without an Errata due to the likes of Harpie's Feather Duster. If it did, maybe make it only return face-up Spells/Traps in a similar fashion to Hey, Trunade!
75. Graceful Charity
Make it so you must Discard 2 first then draw 3 and you cannot add cards from your Deck to your hand outside of Drawing the turn you activvate it.
76. Heavy Storm
If you look at the OCG, they have it at 1 so this card can do the same without any changes. If it did, make it only destroy non-Pendulum Spells/Traps so you can't reset your Pendulum Zones.
77. Kaiser Colosseum
Make it so you need a minimum of 2 monsters, instead of a minimum of 1, for this card to work.
78. Last Will
Make it only able to Special Summon monsters if a monster was destroyed by your opponent's card so you can punish your opponent for using for using certain Removal Effects.
79. Mass Driver
Once/twice/thrice per turn. 'Nuff said.
80. Metamorphosis
Make it so the monster you summon with this effect can't be EARTH, so you can't bring out The Last Warrior from Another Planet or Naturia Exterio.
81. Mirage of Nightmare
Make both its effects 1 single effect so you can't just draw 4, pop this, then keep those 4 cards.
82. Mystic Mine
Replace:
If your opponent controls more monsters than you do
with:
If your opponent controls 2 or more monsters than you do
That way, it'll be much easier for decks to play around it while still heavily limiting plays.
83. Painful Choice
Make it so the cards sent to the GY cannot activate thier effects.
84. Pot of Greed
Make the effect apply to both players.
85. Prematrure Burial
Make it negate the Summoned monster's effects and make it a hard once per turn.
86. Smoke Grenade of the Thief
Replace
When this card is destroyed by a card effect while equipped to a monster
with
When this card is destroyed by a Spell/Trap while equipped to a monster
87. Soul Charge
Like Dimension Fusion (#72), Make it so the monsters cannot be Tributed nor be used as Fusion, Synchro, Xyz, and Link Material the turn they are summoned.
88. That Grass Looks Greener
This card is at 2 in the OCG and isn't seeing play, we might as well leave it alone. Although, we can make it so you cannot activate effects from the GY nor Special Summon from the GY.
89. Zoodiac Barrage
This really doesn't need an errata in my opinion and could come right off the banlist the way it is, but if it needs a nerf, make its destroying effect have to destroy a card other than itself.
90. Appointer of the Red Lotus
Honestly, this card could be unbanned without an Errata. Otherwise, make it so the banished card is returned to the hand during that turn's end phase instead of the opponent's next end phase.
91. Imperial Order
Make it so it negates only specific spell effects instead of just all of them. For example, make this like a permanent Magic Deflector where it negates only Equip, Field, Continuous, and Quick-Play spell effects on the field. Using this to counter very specific spell-heavy strategies like Necrovalley is okay. Using this to completely lock out all spells, including normal, ritual, and pendulum zone spells, is the problem.
92. Last Turn
Make it only target a non-Effect monster just like how it was used in the Anime.
93. Red Reboot
Make it prevent Both players from Activating Trap cards than just the Opponent.
94. Return from the Different Dimension
Just like Dimension Fuson (#72) and Soul Charge (#87), Make it so the monsters cannot be Tributed nor be used as Fusion, Synchro, Xyz, and Link Material the turn they are summoned.
95. Royal Oppression
Make it so that each player can use this card's effect once per turn
96. Self-Destruct Button
Make it so you have to toss a coin, and if the result is heads, both players' life points become 0, but if it's tails, you lose the match.
97. Sixth Sense
Make it so you cannot activate cards or effects from the hand or GY the turn you activate this and make it a hard once per turn. This way, you cannot use the Hand traps you drew nor use monster effects from the GY
98. Summon Limit
Increase the number of monsters each player can summon per turn from 2 to 3 or 4.
99. Trap Dustshoot
Increase the number of cards your opponent must have in their hand to use from 4 to 6 or 7.
100. Ultimate Offering
Make it hard once/twice/thrice per turn.
101. Vanity's Emptiness
Make it so you can only activate it during your turn instead of also the opponent turn.
Wow, what a mouthful.....