"If you lose this battle, you may immediately kill one of your opponent's units that participated in the battle. If that was the last enemy unit, you must still retreat, but your opponent is not considered to have taken the area."
Does this apply only if you are defending, or in any battle? The straight reading of it doesn't say 'defense only' but it's implied by the piece about the opponent taking the area. Also it just seems OP if it applies in attack or defense.
Does this apply only if you are defending, or in any battle? The straight reading of it doesn't say 'defense only' but it's implied by the piece about the opponent taking the area. Also it just seems OP if it applies in attack or defense.