A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages 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, 29 March 2012
Per the rulings given about Jouney's end keep and that neither entrenched position nor footsteps of madness can negate its actions I wanted to confirm that the Shadow's Lair works the same way assuming you have a ninja in play.
Shadow's Lair reads: Ninja Battle: Once per battle, even if this card is bowed and even if you control no units at the current battlefield, target one or more unopposed units with combined total Force of 9 or lower, or one opposed unit: Move each target home; this will not be negated or delayed if you control a Ninja.
Jon Palmer (rules official), 30 March 2012
Per the rulings given about Jouney's end keep and that neither entrenched position nor footsteps of madness can negate its actions I wanted to confirm that the Shadow's Lair works the same way assuming you have a ninja in play.
Shadow's Lair reads: Ninja Battle: Once per battle, even if this card is bowed and even if you control no units at the current battlefield, target one or more unopposed units with combined total Force of 9 or lower, or one opposed unit: Move each target home; this will not be negated or delayed if you control a Ninja.
You are correct.