This is a list of some staples, engines, and cards I find interesting for Master Duel's 2025 N/R Festival. I'm uploading this before we get the banlist, so some cards might be banned or limited like Kashtira Ogre, Brain Control, and Fists of the Unrivaled Tenyi.
Tech Cards
Spirit Shield is a defensive support card for decks that use fiends and zombies. Banish a fiend or zombie from your graveyard to negate an attack once per battle and prevent the destruction of your card(s) once per turn. This card will defend your established board from destruction. Also, it sends itself to the graveyard during either player's end turn if you don't control a fiend or a zombie monster, but that's okay as long as it resolves at least once.
Dimension Slice can target, then banish a face-up monster your opponent controls when you special summon a monster. You can special summon a monster on the opponent's turn with Oasis of Dragon Souls to trigger Dimension Slice. Also, Dimension Slice is an amazing support card for xyz decks because you can activate it the turn it is set if you special summoned an xyz monster.
Odd-Eyes Advance Dragon is a powerful beater that pairs well with Giant Kra-Corn. The Giant Kra-Corn can special summon itself from your hand and redirect an attack towards it when an opponent's monster declares an attack. Odd-Eyes Advance Dragon can be tribute summoned using the Giant Kra-Corn, and it can revive the Giant Kra-Corn from your graveyard when it destroys a monster in battle. You can use Life Hack on Odd-Eyes Advance Dragon to boost its attack to great heights.
D.D.D. - Different Dimension Derby can target, then banish a card on the field if you control a monster that was ritual, fusion, synchro, xyz, or link by using a normal monster as material. Link summoning Imduk the World Chalice Dragon is the easiest way to meet the requirements for Different Dimension Derby. Using a token as material would also work for this card.
Jungle Dweller is level 8 monster that can easily special summon itself from your hand by banishing a light or dark monster from your graveyard. It feels at home in rank 8 decks.
Fire Hand, Ice Hand, and Spiritual Beast Tamer Winda are great defensive cards that can special summon another monster when they're destroyed by an opponent's card. Fire Hand can destroy a monster, then special summon Ice Hand from your deck. Ice Hand can destroy a spell or trap, then special summon Fire Hand from your deck. Spiritual Beast Tamer Winda can special summon another copy of herself or Ritual Beast Ulti-Pettlephin.
Any synchro deck can run an Assault Mode engine consisting of Psi-Reflector, Assault Beast, Assault Sentinel, and Assault Mode Activate to easily summon level 5 to 9 synchros. Assault Sentinel can tribute itself to special summon Psi-Reflector from your hand or deck, but his effect will restrict you into only special summoning synchros from the extra deck for the rest of the turn. Psi-Reflector can search for Assault Beast on normal or special summon. Assault Beast can discard himself to search for Assault Mode. Psi-Reflector can reveal the Assault Mode in your hand to revive an Assault Beast or Assault Sentinel in your graveyard and increase its level by 1 to 4. The engine can even be as compact as 3 Psi-Reflector, 1 Assault Beast, and 1 Assault Mode Activate! Unfortunately, the fatal flaw in both the compact and extended versions of this engine is that it fails if you already have the standard 1 of Assault Mode Activate in your hand and no monsters that Psi-Reflector can revive in your graveyard.
Gravity Collapse is an insane counter trap that synchro decks can play. When your opponent attempts to play the game by summoning a monster, you can send a synchro you control to the graveyard to negate and destroy that summon and prevent your opponent from summoning any more monsters until the end phase (but they can normal set). In short, this card will shut down their turn for a steep price.