The Six Samurai

The Six Samurai (六武衆) are a series of Warrior-type monsters that debuted in Strike of Neos, with further support included in Gladiator's Assault. Their names include "The Six Samurai" or "shien". Them, as well as other related support, rely on having other Six Samurai on the field to use their effects, and as such a Deck revolving around them is often based on swarming the field.

While other cards with "The Six Samurai" are also counted in the series, only the original six have "The Six Samurai -" at the beginning of their names. The overall theme seems to be futuristic, while in some form drawing most inspiration from fuedal Japan.

The basic Six Samurai monsters (the initial '6') all have the effect "If this card would be destroyed you can destroy another "Six Samurai" monster you control instead" and also "While you control another "Six Samurai" monster with a different name, this card can... " referring that their effects activate when another "Six Samurai" monster is on the field.

Strengths and Weaknesses
Six Samurai tend to be flexible enough to be able to respond to most situations, though they are highly dependent on numbers and basic Warrior support cards like "Reinforcement of the Army". They also rely on cards to special summon them. 3 copies of Reasoning was previously used, though after it was limited to 1 in September, people began to use Double Summon or Emergency Teleport to make the deck run faster and to have powerful syncro options. Their support cards help prevent them from being destroyed and they have a number of options for reviving themselves onto the field (including one very costly option that lets up to five of them be revived at once). They also have a strong draw support, Six Samurai United, that acts like a Pot of Greed if you have Grandmaster of the Six Samurai in your hand or another method of special summoning a six samurai, except it is vulnerable to Mystical Space Typhoon and Dust Tornado since it is a continuous spell.

Six Samurai are at their weakest against opponents capable of either swarming the field with strong monsters early in the game faster than this can, or against opponents capable of using card effects that negate special summons (except for Grandmaster of the Six Samurai who can simply return himself to the owner's hand after being destroyed by effects) thereby slowing the swarming ability of the deck (though many decks in the current metagame have that problem).

Aesthetic Trivia
The basic Six Samurai monsters (the initial '6') artwork features each of them holding a weapon which refers to their effects.

The Six Samurai are a reference to the Seven Samurai movie, by Akira Kurosawa.

Each Six Samurai holds a different attribute, and those with polar attributes have opposite effects. Yaichi's opposite is Kamon. Nisashi is Yariza, and Irou is Zanji. While Yaichi destroys face-down spell/trap cards, Kamon destroys face-up ones. Nisashi can attack and potentially destroy several monsters at once, while Yariza bypasses monsters entirely to attack directly. Irou is designed to take down monsters with his own effect before they become a threat, while Zanji can be suicide a D.D. Warrior Lady to take out an already opposing threat. Yaichi, Nisashi and Irou also are all in a calm stance, while Kamon, Yariza, and Zanji are all in action poses (this is because while Kamon stance is calm he's holding some dynamite; and appearing ready to throw it).