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.
Iuchi Jadaran reads: Unicorn Clan • Water • Shugenja • Cavalry • Commander Battle: Move your target Personality to Jadaran's battlefield.
Moto Qu-yuan reads : Unicorn Clan • Samurai • Cavalry • Commander After the resolution of an action that moved a unit: If the unit is now in Qu Yuan's army, straighten it.
My question is can Jadaran target a personality that is already at his battlefied and after the resolution of that action cause the Personality to straightened by Qu yuan?
(C)an (Iuchi) Jadaran target a personality that is already at his battlefield(?)
Yes. This is a variation of, "Is an action legal if an effect can't happen?"
http://rules.l5r.com/CE_FAQ#Is_an_actio ... _happen.3F
(A)fter the resolution of that action cause the Personality to straightened by Qu yuan?
No. Qu-yuan's ability checks for whether movement actually happened.