Can I use Akodo Kobi's reaction while she is not at the current battlefield?
I believe I can because she does not state that she must be there to react. But, there is some question as to that ruling.
Akodo Kobi exp Location
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.
Yes, Reactions aren't subject of the rules of Presence and Location. Kobi XP's "at the current battlefield" means that the dead Personality had to be at a battlefield but it doesn't require her to be there; there are other wordings for marking that ("if XXX is at the current battlefield", "a Personality at XXX's battlefield", "a Personality in XXX's army", etc.)