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Yu-Gi-Oh! Master Duel

Forgotten Underworld Secret Pack

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★Events: NIJISANJI Campaign | Duelist Cup★
★Updates: 12/05 Maintenance | 12/05 Banlist★
★Newly Released Card Packs:
┣ Selection Pack: Aerial Superiority | The End of Guilt★
┗ Secret Packs: Atonement's End | Fruits of the Sinful★

Master Duel Forgotten Underworld Secret Pack
This is a guide on Forgotten Underworld, a Secret Pack in Yu-Gi-Oh! Master Duel. Read on to see all cards available in this Secret Pack and how to unlock it!

List of Contents

Forgotten Underworld: Pack Summary

All Cards
Mementotlan Angwitch Mementotlan Shleepy Mementoal Tecuhtlica - Combined Creation Mementomictlan Tecuhtlica - Creation King Thunder Dragon Colossus Thunder Dragon Titan Mementotlan Twin Dragon Mementotlan Tatsunootoshigo Mementotlan Dark Blade Mementotlan Bone Party Mementotlan Fusion Supply Squad Thunder Dragon Fusion Thunder Dragonhawk Paralyzing Mushroom Thunder Dragonroar Thunder Dragonmatrix Thunder Dragondark Mementotlan-Horned Dragon Mementotlan Mace Mementotlan Goblin Mementomictlan Mementotlan Bone Back Magnum the Reliever Thunder Dragons Thunder Dragon Thunderstormech Cross-Sheep Thunder Dragonlord Thunder Dragonduo Thunder Dragon Thunder Dragon Discharge High Rate Draw Fusion Recovery Polymerization Chain Ignition Mementotlan Ghattic Mementotlan Fracture Dance Mementotlan Cranium Burst Twin-Headed Thunder Dragon Mementotlan Akihiron

Forgotten Underworld: Unlock Conditions

Crafting

★ How to Unlock ★
Craft SR/UR cards within the pack or get them from opening other packs.

Cards to Craft

Key Cards
UR
Thunder Dragon Titan Thunder Dragon Colossus Mementoal Tecuhtlica - Combined Creation Mementotlan Angwitch Mementomictlan Tecuhtlica - Creation King Mementotlan Shleepy
SR
Thunder Dragondark Thunder Dragonmatrix Thunder Dragonroar Thunder Dragonhawk Thunder Dragon Fusion Supply Squad Mementotlan Twin Dragon Mementotlan Tatsunootoshigo Mementotlan Dark Blade Mementotlan Bone Party Mementotlan Fusion Paralyzing Mushroom

Limited-Time Availability

Master Duel - Forgotten Underworld Secret Pack Free Pull

To celebrate the addition of the new Secret Pack, Forgotten Underworld will be available for a limited time to all players along with 1 free Card Pack pull, starting on its release day of April 10, 2025 until June 4, 2025.

After the campaign, players must unlock this Secret Pack much like all other Secret Packs--through crafting SR or UR cards associated with Forgotten Underworld.

Key Cards
UR
Thunder Dragon Titan Thunder Dragon Colossus Mementoal Tecuhtlica - Combined Creation Mementotlan Angwitch Mementomictlan Tecuhtlica - Creation King Mementotlan Shleepy
SR
Thunder Dragondark Thunder Dragonmatrix Thunder Dragonroar Thunder Dragonhawk Thunder Dragon Fusion Supply Squad Mementotlan Twin Dragon Mementotlan Tatsunootoshigo Mementotlan Dark Blade Mementotlan Bone Party Mementotlan Fusion Paralyzing Mushroom

Forgotten Underworld: List of Cards by Rarity

List of Cards
UR ・Thunder Dragon Titan
・Thunder Dragon Colossus
・Mementoal Tecuhtlica - Combined Creation
・Mementotlan Angwitch
・Mementomictlan Tecuhtlica - Creation King
・Mementotlan Shleepy
SR ・Thunder Dragondark
・Thunder Dragonmatrix
・Thunder Dragonroar
・Thunder Dragonhawk
・Thunder Dragon Fusion
・Supply Squad
・Mementotlan Twin Dragon
・Mementotlan Tatsunootoshigo
・Mementotlan Dark Blade
・Mementotlan Bone Party
・Mementotlan Fusion
・Paralyzing Mushroom
R ・Thunder Dragons' Hundred Thunders
・Thunder Dragon Discharge
・Thunder Dragon
・Thunder Dragonduo
・Thunder Dragonlord
・Cross-Sheep
・Thunder Dragon Thunderstormech
・Magnum the Reliever
・Mementotlan-Horned Dragon
・Mementotlan Mace
・Mementotlan Goblin
・Mementomictlan
・Mementotlan Bone Back
N ・Twin-Headed Thunder Dragon
・Chain Ignition
・Polymerization
・Fusion Recovery
・High Rate Draw
・Mementotlan Ghattic
・Mementotlan Fracture Dance
・Mementotlan Cranium Burst
・Mementotlan Akihiron

Yu-Gi-Oh! Master Duel Related Guides

Secret Packs

All Secret Packs & Current Selection Packs

Recommended Secret Packs

List of Recommended Secret Packs
Echo Chamber NationEcho Chamber Nation Wings that Span the SkyWings that Span the Sky
Celestial Dragon and BearCelestial Dragon and Bear The Noble Knights of Crimson FlowersThe Noble Knights of Crimson Flowers
Adventure of Mystical EtchingsAdventure of Mystical Etchings My Cute Lovely FriendsMy Cute Lovely Friends
Master Duel - The Opening Act of an ApocalypseThe Opening Act of an Apocalypse Enchanted Threads of ShadeEnchanted Threads of Shade
Shot Through FictionShot Through Fiction Singular Strike OverthrowSingular Strike Overthrow
Transfigured HeroesTransfigured Heroes Songstress of Sorrow SongSongstress of Sorrow Song
Miraculous AdventMiraculous Advent Alba Abyss Secret Pack BannerAlba Abyss
Number RecallNumber Recall Soldiers of the Storm PackSoldiers of the Storm
Cosmic Mechanical EntitiesCosmic Mechanical Entities Space-Time TranscendentsSpace-Time Transcendents

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