Cyber Dragon

Cyber Dragon's engine opens with Cyber Dragon Core, which on Normal Summon searches any Cyber Spell or Trap — most often Cyber Emergency or Cybernetic Overflow — and treats itself as Cyber Dragon while it sits in the GY. From there, Core's second effect allows it to be banished from the GY to Special Summon a Cyber Dragon monster from the Deck when the opponent controls a monster and you do not, extending the field presence needed to stack Xyz materials. Cyber Dragon Herz and Cyber Dragon Nachster push this further: Herz replaces itself from the Deck or GY when sent to the GY, while Nachster can discard a monster to Special Summon itself and then revive any Machine with 2100 ATK or DEF from the GY — most usefully, the base Cyber Dragon itself.

The deck's primary objective is reaching Cyber Dragon Nova into Cyber Dragon Infinity, a sequence that requires two Level 5 Machine Xyz materials and then one more Xyz Summon on top of Nova. Infinity absorbs Attack Position monsters as additional materials and carries a once-per-turn Quick Effect negation that drains those materials, making it one of the more resilient going-first boards the Extra Deck can offer. Cyber Dragon Vier and Cyber Dragon Drei provide Level 5 bodies to accelerate that route, with Vier entering from hand whenever another Cyber Dragon is summoned and Drei levelling up the board on Normal Summon.

Supporting the Fusion route, Cyber Repair Plant recycles LIGHT Machines and Cybernetic Overflow generates removal by banishing Cyber Dragons of differing Levels — and replaces itself with a Cyber Spell or Trap if destroyed, meaning the opponent risks granting card advantage by attempting to clear it. Cyber Eternity Dragon, fused with Cyberload Fusion using banished monsters as material, adds a resilient defensive layer that cannot be targeted or destroyed by card effects while a Machine Fusion sits in the GY.