Also, who benefits more from the Fury rune, Kika or Snowe? Depends how they're being used and what their ATK stats are. if Kika will always use Falcon and Snowe+Hero will always use True Friendship unite, then whoever has higher ATK will benefit more since it increases the ATK value by 50%. Also, if you're not worried about defense too much. can either one equip the Ogre Set? cuz that will give Fury status and the Fury Rune can go to a character who can't equip the Set.
you can analyze it further, too... like if only one is using Double-Strike, then putting Fury on the Double-Strike character will be better. there's a set that increases ATK by 20%, so that plus Fury Rune plus Double-Strike will give you nice results.