The Stronghold Shiro no Soshi was first released during Code of Bushido, the last Diamond-Lotus legal expansion before Lotus Edition itself. Featuring a new mechanic, ninjutsu, it was designed to be the military answer for the Scorpion Clan in Lotus, replacing the role The Towers of the Yogo had in Diamond.
- Non-Unique Ninja you own without Ninjutsu have the Ninjutsu trait with a value equal to their printed Gold cost minus 6 (minimum 0). Each time you would reveal a Dynasty card during the Events Phase, you may look at it, then choose not to reveal it if it is a Ninjutsu Personality.
- Open: Any number of times per turn: Target a face-down Ninja who has not been targeted by anything this turn. Give him +2F until the next time he is targeted or the turn ends.
Most ninja (and ninjutsu personalities, by association) printed after Diamond Edition have printed reactions that punish the opponent for targetting them, such as Shosuro Tsuyoshi and Shosuro Saemon. Shiro no Soshi (SnS) encourages a blitz build, where the player buys personalities out fast and attacks early with the force-boost that the stronghold itself gives until they are targetted, after which the personality's own reaction punishes the opponent for doing so.
The main problem that many SnS players face with this decktype is that ninjutsu has a gold cost associated with flipping the ninjas face up: this means that the gold-to-personality ratio is rather delicate and prone to failing at the worst moments. In addition, many ninja reactions require multiple targettings in the correct order of personalities for it to be truly effective (see: Bayushi Kan and Bayushi Shun), and the Scorpion player has little control over who gets targetted.