N/R Labrynth

This deck focuses on unleashing an onslaught of traps, then pushing for game with Labrynth Archfiend.

Archfiend Playtime can special summon Labrynth Archfiend from your hand or deck, Labrynth Archfiend can special summon itself from your hand if a trap is activated, and Call of the Archfiend can special summon Labrynth Archfiend from your graveyard by discarding a fiend.

Archfiend's Usurpation can search for any of your Archfiend traps, including the floodgate Simul Archfiends, which can prevent your opponent from special summoning a Ritual, Fusion, Synchro, Xyz, or Link monster if they already control a monster with one of the aforementioned card types.

Supporting this strategy is a small fiend engine consisting of Fiendish Rhino Warrior, Diabolica the Draconique General, and the Terrifying Toddler of Torment. If Fiendish Rhino Warrior is sent to your graveyard, then you can send a fiend from your deck to the graveyard. If you send the Toddler of Torment from your deck to your graveyard, then you special summon it in face-down defense position. If the Toddler of Torment is flipped face-up, then you can send another fiend from your deck to your graveyard. If you send Diabolica from your deck to your graveyard with a card effect, then you can add a fiend, except Diabolica, from your graveyard to your hand.

A basic resource loop you can do is:

1. Send Fiendish Rhino Warrior to your graveyard.

2. Activate Fiendish Rhino Warrior's effect to send Diabolica the Draconique General from your deck to your graveyard.

3. Activate Diabolica's effect to add Fiendish Rhino Warrior back to your hand.

This loop gives you a spare fiend in your hand to use as discard fodder. Also, Terrifying Toddler of Torment can start this loop with its flip effect.

Edit: This deck now uses a Subterror Succession engine to search for almost every fiend in the main deck!

Using Subterror Succession

Subterror Succession's first effect can send a monster from your hand or a face-up monster on your field to the graveyard to search for a Flip monster with the same attribute, but a different name:

• Send a Dark attribute monster to search for Terrifying Toddler of Torment.
• Send an Earth attribute monster to search for Subterror Behemoth Speleogeist.
• Send a Fire attribute monster to search for Helshaddoll Hollow.

Subterror Succession's second effect can send a Flip monster from your hand or a face-up monster on your field to the graveyard to search for a Flip monster with the same attribute, but a lower level:

• Send Terrifying Toddler of Torment to the graveyard to search for Labrynth Stovie Torbie or Soul Scissors.
• Send Subterror Behemoth Speleogeist to search for Fiendish Rhino Warrior.
• Send Helshaddoll Hollow to search for Zalamander Catalyzer.

Subterror Succession's effects can trigger Labrynth Stovie Torbie and Labrynth Chandraglier's graveyard effects. Also, Subterror Succession, like Call of the Archfiend and Paleozoic Dinomischus, sends a card to the graveyard as part of its effect, so it can trigger the graveyard effects of Helshaddoll Hollow and Diabolica the Draconique General.

Some Tips

Labrynth Chandraglier and Labrynth Stovie Torbie's effects send cards to the graveyard as part of their costs, so they won't trigger Helshaddoll Hollow or Diabolica the Draconique General's graveyard effects.

Terrifying Toddler of Torment and Fiendish Rhino Warrior can trigger their graveyard effects if they're sent to the graveyard by the effects of Labrynth Chandraglier and Labrynth Stovie Torbie.

Farewelcome Labrynth can set any non-Labrynth normal trap from your hand or deck. This effect can search for Subterror Succession or Archfiend Playtime.

Baba Barber is a fiend link 2 that requires any 2 monsters as material. You can use Paleozoic Dinomischus as material to summon her. Her being a fiend allows you to activate Farewelcome Labrynth, and trigger the revival effect of Diabolica the Draconique General.

Helshaddoll Hollow and Subterror Behemoth Speleogeist are level 5 or higher fiends, so you can revive them with Call of the Archfiend.

Diabolica the Draconique General has an effect that allows you to special summon her from your hand or graveyard if a fiend is sent to the graveyard by a card effect. You can wipe the field with Torrential Tribute, then activate Diabolica's effect if a fiend is destroyed.

Replacements for Labrynth Archfiend

These monsters are some replacements for Labrynth Archfiend in case it gets banned or limited by an N/R banlist. The Archfiends can be special summoned from your hand or deck with Archfiend Playtime.

Beast of Talwar - The Sword Summit, which is always treated as an Archfiend card, can special summon itself from your hand if you control no monsters, it has decent attack, and, once per turn, it can't be destroyed by your opponent's card effects. It serves as a big guy to instantly pressure on your opponent.

Archfiend's Advent can steal an opponent's monster until the end phase if it's normal or special summoned. Normally, you'd special summon it with Archfiend Playtime or Call of the Archfiend to disrupt your opponent's play or break their board by stealing one of their monsters. It's also a level 6 fiend, so you can use it as xyz material for D/D/D Wave High King Caesar. Puzzlomino, the Drop-n-Deleter can manipulate one of your monster's levels to help you summon Wave High King Caesar. Lastly, one of Archfiend's Advent's underrated effects boosts your other monster's attack by 500 during your turn only, helping you finish games quicker.