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, 14 June 2011
What happens if I use Jeng-Yun on a personality then use Enticement on him?
Can I attack with him?
Jeng-Yun Fear Limited: Taget another player's Personality. After the Cavalry Maneuvers Segment this turn, you may assign him, even if he is not at home, to a battlefield where you control one or more units.
Enticement Open: Pay Gold equal to the total Gold Cost of the targeted Personality's unit: Lose 3 Honor. Take control of a target Personality. While you control him, you may not assign his unit to attack and he will not move to attack. Before this turn ends, give control of him to his owner.
Zen Faulkes (rules official), 15 June 2011
What happens if I use Jeng-Yun on a personality then use Enticement on him? Can I attack with him?
No. "You may not assign his unit to attack" is the most recent effect and has priority.
Alex Jones (rules official), 15 June 2011
You may not assign the Personality.
An effect that states that you "may not" do something will always override an effect that says "you may" do something: see "May not" for more details.
Alex