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.
Under 20F rules, can Brazen Disregard stop the movement from an Accessible Terrain?
The 20F rules state "The source is the card that the effect, action or targeting is printed on, or the rulebook if it is printed there" and "Effects of traits and abilities given to other cards, copied from other cards, or on created cards, come from the card they are on.", making no mention of players being a possible source.
Under 20F rules, can Brazen Disregard stop the movement from an Accessible Terrain?
The 20F rules state "The source is the card that the effect, action or targeting is printed on, or the rulebook if it is printed there" and "Effects of traits and abilities given to other cards, copied from other cards, or on created cards, come from the card they are on.", making no mention of players being a possible source.
In this case, Accessible Terrain is still the source of the effect, as it does not fit either of the exceptions listed under "From". Brazen Disregard will stop it.
For clarification, note that you must use Brazen Disregard to Interrupt the Absent Repeatable Battle; playing it to Interrupt the Absent Battle that puts Accessible Terrain into play will NOT prevent all movement from Accessible Terrain.