The archetype's Main Deck monsters focus broadly on three key effects: Searching for specific cards, Summoning monsters, and Recycling previously used cards. These Main Deck monsters are split between two categories:
- Gemini Monsters, which have many powerful effects that are used primarily to initiate combos.
- Non-Gemini Monsters, which focus on creating a defensive wall by reacting to destruction.
Among the Gemini Monsters, "Vita" and "Lucrum" Summon other Gemini Monsters (from the Deck, and the Graveyard respectively); "Fratres" and "Genitor" focus on destroying cards on the field (monsters, and Spells/Traps respectively); "Regnum" searches for other Gemini Monsters; "Amicitia" can potentially destroy a great number of Spells/Traps on the field; "Carcer" protects Gemini Monsters that you control.
Among the non-Gemini Monsters, "Nati" is the heart of the engine, and can Special Summon any of the archetype's non-Gemini Monsters from the Graveyard, with the condition that it is destroyed during the End Phase; "Valetudo" and "Uxor" are similar, and Summon specific monsters from the Deck when destroyed (non-Gemini Monsters, and Gemini Monsters respectively); "Mors" and "Iter" are also similar, and both feature two effects - Mors will search for any 'Archshade' card during the End Phase of the turn it was sent to the Graveyard, and can be banished from the Graveyard to give a Gemini Monster its effects (without the need to Normal Summon it twice). Iter will Special Summon Psychic-Type Tuner monsters with low ATK when sent to the Graveyard, and can be banished from the Graveyard to let you additional Normal Summon 1 Gemini Monster.