EARTH

2 Flip monsters Gains ATK equal to the combined original Levels of the "Subterror" monsters used for its Link Summon x 100. During your Main Phase: You can send 1 Flip monster from your Deck to the GY, and if you do, Special Summon 1 monster from your hand in face-down Defense Position to your zone this card points to. You can only use this effect of "Subterror Behemoth Fiendess" once per turn. Once per turn, if a monster this card points to is flipped face-up: Add 1 Flip monster from your Deck or GY to your hand.

EARTH 1

When your opponent activates a card or effect (Quick Effect): You can send this card from your hand or field to the GY, then target 1 "Subterror" monster you control; negate the activation, then change the targeted monster to face-down Defense Position. You can target 1 face-up monster you control; change it to face-down Defense Position, and if you do, Special Summon 1 "Subterror" monster from your hand or GY, in face-up or face-down Defense Position. You can only use each effect of "Subterror Fiendess" once per turn.

DARK

2+ monsters with different names If this card is Link Summoned: You can discard 1 card, then target 1 card on the field; shuffle it into the Deck, then, if this card was co-linked when this effect was activated, you can draw 1 card. You can only use this effect of "Knightmare Unicorn" once per turn. While any co-linked "Knightmare" monsters are on the field, for your normal draw in your Draw Phase, draw 1 card for each different card name among those co-linked "Knightmare" monsters, instead of drawing just 1 card.

EARTH 7

FLIP: You can target 1 monster your opponent controls; banish it. You can only use this effect of "Subterror Behemoth Umastryx" once per turn. When a face-up monster you control is flipped face-down, if you control no face-up monsters: You can Special Summon this card from your hand in Defense Position. Once per turn: You can change this card to face-down Defense Position.

Spell Field

When this card is activated: You can add 1 "Subterror" monster from your Deck to your hand. Once per turn: You can change 1 face-down Defense Position "Subterror" monster you control to face-up Attack or Defense Position. Once per turn, when an opponent's monster declares an attack: You can change 1 face-down Defense Position "Subterror" monster you control to face-up Attack or Defense Position, then you can negate the attack. You can only activate 1 "The Hidden City" per turn.

Spell Normal

Excavate the top 3 cards of your Deck, add 1 of them to your hand, also, after that, shuffle the rest back into your Deck. You can only activate 1 "Pot of Duality" per turn. You cannot Special Summon during the turn you activate this card.

Trap Normal

When there are 4 or more monsters on the field: Destroy all face-up monsters.

EARTH

2 Level 4 monsters Once per turn: You can detach 1 Xyz Material from this card, then target 1 Beast, Beast-Warrior, or Winged Beast-Type monster you control and 1 other card on the field; destroy them.

WATER

2 Level 4 monsters While this card has a material attached that was originally WATER, all WATER monsters you control gain 500 ATK. Once per turn (Quick Effect): You can detach 1 material from this card; your opponent cannot activate any card effects in their GY this turn.

FIRE

2 monsters with different names If this card is Link Summoned: You can discard 1 card, then target 1 Spell/Trap your opponent controls; destroy it, then, if this card was co-linked when this effect was activated, you can draw 1 card. You can only use this effect of "Knightmare Phoenix" once per turn. Co-linked monsters you control cannot be destroyed by battle.

Trap Normal

Activate 1 of these effects, also, after that, Set this card face-down instead of sending it to the GY. ● Change 1 Set "Subterror" monster on the field to face-up Attack or Defense Position. ● Change 1 face-up "Subterror" monster on the field to face-down Defense Position. ● ATK/DEF of 1 "Subterror" monster on the field become equal to its combined original ATK/DEF until the end of this turn. ● This turn, activated effects of "Subterror" cards cannot be negated.

Spell Quick

Target 1 face-up monster on the field; change that target to face-down Defense Position.

Trap Normal

Target 1 card your opponent controls and 1 card in their GY; send that card on the field to the GY, and if you do, Set the other card from the GY to your opponent's field. You can only activate 1 "Terrors of the Overroot" per turn.

DARK

3+ Effect Monsters Neither player can target this card with monster effects. Once per turn (Quick Effect): You can target 1 face-up monster on the field; it loses 500 ATK/DEF. Your opponent cannot activate cards or effects in response to this effect's activation. At the start of the Damage Step, if this card attacks an opponent's monster: You can place that opponent's monster in a zone this card points to and take control of it, but send it to the GY during the End Phase of the next turn.

LIGHT

2 Level 4 monsters Once per chain, during your Main Phase or your opponent's Battle Phase, if your opponent has more total cards in their hand and field than you do (Quick Effect): You can detach 1 material from this card; destroy all other cards on the field, also your opponent takes no further damage this turn.

EARTH 12

FLIP: You can change all other face-up monsters on the field to face-down Defense Position. You can only use this effect of "Subterror Behemoth Ultramafus" once per turn. When a face-up monster you control is flipped face-down, if you control no face-up monsters: You can Special Summon this card from your hand in Defense Position. Once per turn: You can change this card to face-down Defense Position.

EARTH

2 monsters with different names If this card is Link Summoned: You can discard 1 card, then target 1 Special Summoned monster in your opponent's Main Monster Zone; destroy it, then, if this card was co-linked when this effect was activated, you can draw 1 card. You can only use this effect of "Knightmare Cerberus" once per turn. Co-linked monsters you control cannot be destroyed by card effects.

DARK

2 Effect Monsters If your linked monster attacks a Defense Position monster, inflict piercing battle damage to your opponent.

Spell Normal

Add 1 Field Spell from your Deck to your hand.

EARTH 4

FLIP: You can add 1 "Subterror" card from your Deck to your hand, except "Subterror Guru". You can target 1 other face-up monster on the field; change that monster, also this card, to face-down Defense Position. This is a Quick Effect if you control another "Subterror" card. You can only use each effect of "Subterror Guru" once per turn.

EARTH 1

When your opponent activates a card or effect (Quick Effect): You can send this card from your hand or field to the GY, then target 1 "Subterror" monster you control; negate the activation, then change the targeted monster to face-down Defense Position. You can target 1 face-up monster you control; change it to face-down Defense Position, and if you do, Special Summon 1 "Subterror" monster from your hand or GY, in face-up or face-down Defense Position. You can only use each effect of "Subterror Fiendess" once per turn.

EARTH 4

FLIP: You can add 1 "Subterror" card from your Deck to your hand, except "Subterror Guru". You can target 1 other face-up monster on the field; change that monster, also this card, to face-down Defense Position. This is a Quick Effect if you control another "Subterror" card. You can only use each effect of "Subterror Guru" once per turn.

DARK

3+ Effect Monsters Neither player can target this card with monster effects. Once per turn (Quick Effect): You can target 1 face-up monster on the field; it loses 500 ATK/DEF. Your opponent cannot activate cards or effects in response to this effect's activation. At the start of the Damage Step, if this card attacks an opponent's monster: You can place that opponent's monster in a zone this card points to and take control of it, but send it to the GY during the End Phase of the next turn.

DARK

2+ monsters with different names If this card is Link Summoned: You can discard 1 card, then target 1 card on the field; shuffle it into the Deck, then, if this card was co-linked when this effect was activated, you can draw 1 card. You can only use this effect of "Knightmare Unicorn" once per turn. While any co-linked "Knightmare" monsters are on the field, for your normal draw in your Draw Phase, draw 1 card for each different card name among those co-linked "Knightmare" monsters, instead of drawing just 1 card.

EARTH

2 Flip monsters Gains ATK equal to the combined original Levels of the "Subterror" monsters used for its Link Summon x 100. During your Main Phase: You can send 1 Flip monster from your Deck to the GY, and if you do, Special Summon 1 monster from your hand in face-down Defense Position to your zone this card points to. You can only use this effect of "Subterror Behemoth Fiendess" once per turn. Once per turn, if a monster this card points to is flipped face-up: Add 1 Flip monster from your Deck or GY to your hand.

WATER

2 Level 4 monsters While this card has a material attached that was originally WATER, all WATER monsters you control gain 500 ATK. Once per turn (Quick Effect): You can detach 1 material from this card; your opponent cannot activate any card effects in their GY this turn.

Spell Quick

Target 1 face-up monster on the field; change that target to face-down Defense Position.

Spell Normal

Excavate the top 3 cards of your Deck, add 1 of them to your hand, also, after that, shuffle the rest back into your Deck. You can only activate 1 "Pot of Duality" per turn. You cannot Special Summon during the turn you activate this card.

Spell Normal

Add 1 Field Spell from your Deck to your hand.

Spell Field

When this card is activated: You can add 1 "Subterror" monster from your Deck to your hand. Once per turn: You can change 1 face-down Defense Position "Subterror" monster you control to face-up Attack or Defense Position. Once per turn, when an opponent's monster declares an attack: You can change 1 face-down Defense Position "Subterror" monster you control to face-up Attack or Defense Position, then you can negate the attack. You can only activate 1 "The Hidden City" per turn.

Trap Normal

When there are 4 or more monsters on the field: Destroy all face-up monsters.

Trap Normal

Target 1 card your opponent controls and 1 card in their GY; send that card on the field to the GY, and if you do, Set the other card from the GY to your opponent's field. You can only activate 1 "Terrors of the Overroot" per turn.