Dark World deck with the new structure deck - thought i'd make this as I've seen a lot of deckbuilding mistakes in other dark world decks recently. Below I've explained the choices in tech cards/side deck cards and the choices that differ from most other dark world decks i've seen
-Reign-Beaux at 1 - it does nothing on the field, but is a useful extender so I would either have 1 or 2 copies, three isn't necessary
-Grapha at 2 - Due to searchability through Snoww and Reign-Beaux in addition to the decks fantastic draw power, 2 copies is all that is necessary
-Sillva at 1 - Searchable as above, plus, in combination with Ceruli and Akashic Magician, there is a recurrable anti-Fenrir loop where Ceruli being on your opponents side of the field will prevent Fenrir summons
-Gates at 2 - it's the most searchable card in the deck - it is also very rare that duels last long enough for 3 copies to be needed. The third copy never came up in testing
-Allure of Darkness over Dark World Dealings - DWD lets your opponent discard. Against Tears this is a big no-go. Side in DWD only after you know what your opponent is playing
-Mothman in side deck - Mothman is in the side deck because of the same reason DWD is in the side deck, only side in if you know your opponent is not playing Tearlaments
-Bigfoot and Nessie at 3 - As for Bigfoot, this is because the deck will contain more level 8s will synergise with Grapha for more drawpower from trade-in as well as provide more material for Hope-Harbinger, which will also combo with Ceruli for Fenrir-hate. Additionally, Bigfoot is good removal for D Fissure and Macro Cosmos now that they are unlimited as these anti-tear cards will be common in the current meta but are also very strong against DW. Nessie is at 3 over Thunderbird or Chupacabra (common picks in other DW decks) because it provides an additional search to get to Bigfoot, which is good for reasons already described.
-Mask Change and dark law package - Mask Change II synergises well with the play style - additionally, banish from hand is broken against almost anything that isn't Floo
-Zalamander Catalyzer in side - free special summon of itself or a DW monster and becomes a 1 card resource loop
Other good tech choices: Gozen Match, Infip, Zephyros, Skill Drain, Dark World Punishment, Thunderbird, Chupacabra, Beginning of The End, Dark Ruler no More
Feel free to give feedback!