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, 27 February 2008
I have a personality (without any abilities) which was targeted by Gempukku Ceremony. I attack with him and my opponent does not defend (no defending personalities). If I use now the Battle action from the Gempukku Ceremony, does he have to discard 2 cards, because he can't send anybody home?
Gempukku Ceremony Limited: Target one of your Personalities with no abilities. Permanently give him the ability, "Battle: Bow and move home this Personality: The enemy leader may discard two cards. If he does not, he chooses and moves home a Personality in his current army."
Doruk Özaydın (rules official), 28 February 2008
I have a personality (without any abilities) which was targeted by Gempukku Ceremony. I attack with him and my opponent does not defend (no defending personalities). If I use now the Battle action from the Gempukku Ceremony, does he have to discard 2 cards, because he can't send anybody home?
No, per Choices: "A choice may be made even if its consequences would be negated or otherwise fail due to lack of suitable things to affect."