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, 1 December 2011
Situation:
Yoritomo Sachina (XP) takes control of another player's personality (who we will call Dude A). On a subsequent turn, Dude A defends a province against an attacking army. Through some myriad of effects, Sachina leaves play during the battle. Dude A is then returned to his owner's control. Is Dude A at the battle in his owner's army, or at his owner's home?
Relevent Text:
Political Limited: Once per game, target a Personality, pay Gold equal to his unit's total Gold Cost plus four, and bow Sachina: Take control of him. After the next time this game Sachina leaves play, give control of him to his owner.
Zen Faulkes (rules official), 1 December 2011
Yoritomo Sachina (XP) takes control of another player's personality (who we will call Dude A). On a subsequent turn, Dude A defends a province against an attacking army. Sachina leaves play during the battle. Dude A is then returned to his owner's control. Is Dude A at the battle in his owner's army, or at his owner's home?
Owner's army.
http://rules.l5r.com/CE_Physically_mark ... rd_control: "When a non-attachment card changes control, it goes... to its new controller’s side of the battlefield if it was at a battlefield before changing control."