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, 30 May 2013
If my opponent plays caught unawares/hidden defenses and I only control 2 targets either at home or at the battlefield would I be able to use a redirect to have only 1 personality bow?
For example, I buy two Utaku Eun-jus and I have a Benten's Blessing on the board. My opponent plays Caught Unawares to bow both of my people and I don't have any know no fears in hand. Can I use benten's reaction and redirect to ensure one stays straight or does caught unawares/hidden defenses automatically bow 2 no matter what unless you have Emerald Armor, Arcane Cloak or Know no fear?
A player, 30 May 2013
You can't have two simultaneous instances of targeting on the same card, so no, you can't turn two targets into one by means of redirection. See here: When multiple targets are chosen simultaneously, the same target cannot be chosen twice. This also means that when one target out of multiple, already-chosen targets is being changed, another one of those already-chosen targets cannot legally become the new target. Example: If you target a Samurai and a Shugenja simultaneously, another player cannot change your targeting of the Samurai to target that Shugenja, because you have already chosen the Shugenja for the same targeting.
Note that Emerald Armor and Arcane Cloak interfere with targeting and therefore may not be able to work against cards making multiple simultaneous targets, if they suddenly become the only (remaining) legal choice available in the middle of these multiple targets.