"Holon" is a archetype used by monsters.
Types of Cards
There is a large variety of "Holon" cards, and they include monsters, spells and traps.
The Holon monsters all have "Holon" in its name, hence the fact that "Holon is the archetype.
The Holon spell cards support Holon monsters or can only be used if there is a Holon monster on the field.
The Holon trap cards support Holon monsters or can only be used if there is a Holon monster on the field.
"King Holon" is an archetype belonging to only some monsters. "King Holon" monsters are also "Holon" monsters. The "King Holon" monsters are extremely powerful effect monsters. There can only be one "King Holon" monster on the field at a time. Most of them have a different type, but might repeat attributes. They can all be special summoned by having "Holon" monsters in the graveyard and by having another one on the field and switching them.
"Zwak" versions of King Holon cards are weaker versions. They are found in non-Holon packs. "Zwak" means "weak."
List of Booster Packs with Holon Cards
(36 Holon cards)
(18 Holon cards)
(?? Holon cards)
(2 Holon cards)
(1 Holon card)
Here is a list of Holon cards from both Holon Packs and Other Packs.
Holon Packs Card List