This is the first set to identify "Archfiend" as an archetype and as such contains more "Archfiend" monsters and support cards. It includes the chess-themed "Archfiend" cards and an Ultimate Rare reprint of "Archfiend of Gilfer". It also contains cards from the Battle City arc, mainly the ones used by Ishizu Ishtar.
Each pack contains 5 cards and each box contains 30 packs.
There are 53 cards it total, or 57 in the Master Set.