Normally, they confine themselves in deepest depths of stormy mountains training themselves, but once a month each year, they cause a great storm that descends to the lands below. People recognize their power as a natural phenomenon that transcends human understanding.
The archetype name, "妖仙獣", is composed of 3 Kanji characters. "妖" yō ("strange"; "attractive") refers to magical creatures and practices (such as yōkai, yōsei, yōki, yōjutsu). "仙" sen ("hermit") refers to immortal spirits that train themselves in hidden places for thousands of years to become magical, usually to turn from minion demons into gods. 獣 ("beast") refers to the beast-like appearances of the archetype.
The "Yosenju" monsters are all based off of elements of Japanese mythology and folklore — especially yōkai — with wind-based powers. Several of the members are based on the Kamaitachi. In folklore these were weasel-like creatures that rode on whirlwinds, looking to cut unsuspecting passers-by with sickles and nails.
"Yosenju Misak" is specifically based on a similar creature called the "Yama Misaki" – a demonic wind which takes on the shape of a human's severed head riding the air using fallen souls as a wheel.
The Pendulum Monsters of the archetype lean more into the realm of Shinto symbolism than Folklore. "Shinchu R" and "Shinchu L" represent halves of a Torii Gate, which are used to mark a boundary between the realms of the profane and sacred with "Mayosenju Daibak" representing an enshrinedKami in a state of destructive anger. Interestingly, "Daibak" draws inspiration from both the "Kamaitachi" Yokai and the notion of "Divine Wind" or "Kamikaze".
The "Yosenju" monsters' primary strategy focus on swarming the field through sequenced Normal Summons; they also can perform Pendulum Summons. They share a Spirit-esque effect that causes them to return themselves to the hand at the end of the turn when Normal or Special Summoned, with the exceptions of "Yosenju Shinchu L" and "Yosenju Shinchu R"; these two last ones focus on protecting the on-Field "Yosenjus" from attacks or card effects as well as on setting up Pendulum Summons.
The previously-mentioned "Mayosenju Daibak" is the current ace card of the theme, and bounces 2 cards on the Field upon its Normal or Special Summon; this effect can be used to deal with cards that would be difficult to get rid of, such as "El Shaddoll Winda", "Beelze of the Diabolic Dragons", "Fire King High Avatar Garunix", etc, or to recycle its owner's own cards, such as "Fiendish Chain", etc. Despite its high Level normally rendering it too difficult to Pendulum Summon, the Pendulum Effect of "Yosenju Shinchu R" raises its Pendulum Scale to 11 in order to facilitate this task. As a Pendulum Card, "Daibak" can boost the ATK of your attacking "Yosenjus" by 300 during the Battle Phase only.
The Support cards of the Archetype also rely on keeping card advantage, by either returning an opponent's card to the hand when a "Yosenju" monster do so, or by returning a monster to the Deck, instead. "Yosen Training Grounds" can accumulate Counters — as the "Yosenju" monsters are Normal or Special Summoned — in order to give them even more power, by either boosting their ATK, or by fetching or retrieving the cards needed to keep the player up with the game. In order to protect them against anything that would try to frustrate their offensiveness, there is "Yosenjus' Secret Move", a Counter Trap Card that can negate the activation of any card or effect and destroy that card, provided you control another face-up "Yosenju" card.
Some off-theme cards that may be useful:
"Divine Wind of Mist Valley": Due to the effect that returns them to the hand, this card can serve to swarm the Field even more, by Special Summoning a "Yosenju" monster from the Deck when another one returns to the hand during the End Phase; it is more recommended to Special Summon "Shinchu R" or "L", that would use their Continuous Effects to protect the other monsters from attacks or targeting effects.
"Fire Formation - Tenki": it is a staple in this Deck, since it can search any of the "Yosenju Kama 1", "2" or "3" and can even be recycled by the effect of "Daibak".
"Spring of Rebirth": It is possible to Normal Summon up to 5 Level 4 "Yosenju" monsters per turn; this card can give you up to 2500 LP per turn if used alongside them.
One of the main drawbacks of a "Yosenju" deck is its susceptibility of having a blank Field, since most of the time, the "Yosenju" monsters will return to the hand. This increases its vulnerability against beatdown Decks that are capable of swarming the Field and attacking with brute force.
"Summon Breaker" and "Summon Limit" can be useful against the successive Normal Summons; "Mistake" can stop "Fire Formation - Tenki", "Yosenju Kama 3", "Yosenju Oyam" and "Yosen Training Grounds", but "Yosenju Kama 1" can easily bounce them, so these opposing cards may be only a temporary, situational threat.
"Degenerate Circuit" can easily banish them when "Yosenju" monsters will return to the hand.
This Deck usually has 3 copies of "Yosenju Kama 1", "2" and "3", so "Chain Destruction" may be useful as it can potentially sever the main arsenal of the Deck.
"Skill Drain" is also a good solution, as it simply negates their effects, which means that no card will be searched by "Kama 3" and no card will return to the hand by "Daibak" and "Kama 1".
As the main offensive strategy of a Yosenju deck is to send opponents monsters back to the hand with Kama, cards then are unaffected by card effects that are useful. "Number 86: Heroic Champion - Rhongomyniad" can achieve this if at least three materials can be used. This monster can be used easily in Tellarknights, as well as "Stellarknight Alpha", which can be equipped to a Tellarknight Xyz monster for an attack boost and protection from card effects. Anything than can successfully get two level four, dark type monsters on the field can use "Evilswarm Thanatos" to the same effect. Monarchs and any tribute stun deck can use "The Monarchs Awaken" and "The Monarchs Erupt" as well, which can be easily searched with "Tenacity of the Monarchs."