A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from the Wayback Machine (its copy), so posts it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 12 October 2005
Castle Of the swift sword:
Once per turn, if you control a Tacttician at the battlefield,You may play a formation as a normal action card for one of its abilities ignoring "formed by" requirements.
Sadahigi:
Battle: If Sadahige is in the current battle, once per battle, play an Action card from your discard pile for one of its Battle actions as if it were in your hand. Remove the card from the game.
Itagi:
Political Battle: Once per turn: Look at a number of cards from the top of your Fate deck equal to the number of Lion Clan Personalities you control at the current battlefield. You may play one Action card from those cards for an Open or Battle action printed on it.
Can you use Sadahige or Itagi to get a formation card , lets say Direct Assault, and then play it as if it were just a regular action card with the stronghold?
Jeff Alexander (rules official), 12 October 2005
Castle Of the swift sword:
Once per turn, if you control a Tacttician at the battlefield,You may play a formation as a normal action card for one of its abilities ignoring "formed by" requirements.
Sadahigi:
Battle: If Sadahige is in the current battle, once per battle, play an Action card from your discard pile for one of its Battle actions as if it were in your hand. Remove the card from the game.
Itagi:
Political Battle: Once per turn: Look at a number of cards from the top of your Fate deck equal to the number of Lion Clan Personalities you control at the current battlefield. You may play one Action card from those cards for an Open or Battle action printed on it.
Can you use Sadahige or Itagi to get a formation card , lets say Direct Assault, and then play it as if it were just a regular action card with the stronghold?
Yes.