This has been asked a few times in the middle of other threads, but not answered. I'm going to formalize this question. What is the full meaning of 'friendly'?
In the current rules reference, there is 1 instance of friendly. It appears on page 5, as the first bullet point under Cost.
QuoteWhen a player is paying a cost, the payment must be made with cards and/or game elements that player controls. The word “friendly” is used as a reminder of this in some costs.
This appears to mean that 'friendly' is simply anything that you control (fate, characters, attachments, etc.). This yields my reason for questioning this: Blackmail.
Suppose someone (not me, of course) were playing Crab w/ Scorpion.
Blackmail:
Quote3 Cost, 3 Influence
Play only if you are less honorable than your opponent.
Action: During a conflict, choose a character with printed cost 2 or lower controlled by your opponent – take control of that character until the end of the conflict.
Funeral Pyre:
QuoteStrength: +0.
Action: Sacrifice a (friendly) character – draw 1 card.
Way of the Crab:
Quote1 Cost
Action: Sacrifice a (friendly) character. Choose an opponent – that player must sacrifice a character. (Max 1 per round.)
Playing multiple copies of Blackmail in 1 turn is technically possible (doubly if you hold fate over between rounds). Getting these three to trigger in 1 turn isn't out of the question, but getting just 2 of these to trigger in 1 turn is quite plausible.
While playing against Crab (as Dragon) I already need to make sure I have cannon fodder in play at all times because Way of the Crab is playable during the Dynasty phase. If, on top of that, I need to have multiple (cannon fodders? cannons fodder?) characters to be potentially sacrificed, or to have only 3+ costed characters, 1 of which can be sacked, then that threat is going to eat up most of my fate and strategy until I can establish which allied clan my opponent is running.
If, instead, friendly means cards/fate/honor that you own and control, then this line of thinking is moot.