Just a thought. New ability/bonus that boosts the next card played.
Defeat: Assist: +2 Damage/Power. When you lose with this card, the next card you use is assisted with +2 damage/power.
Defeat: Assist: Protection: Power/Damage. When you lose with this card, the next card you use gains Protection: Power/Damage
Can make + Life per Damage cards even more deadly if you have + damage, can make some 1HKOs for La Junta
/Fang Pi Clang
(even in ELO), can make All Stars
create nice power gaps if + power, etc.
Can also make your opponent think about putting an extra SoA into the deck (could bring Stop: Ability cards into play?)
I'm sure there could be some sort of balance by looking through the cards, but the idea is lose with 1 card, then the next card becomes stronger (or maybe make opponent's card weaker).
Or, maybe even change the ability to Cripple (probably not Bonus, since they'd probably all be splash cards).
Cripple: -2 Damage/Power. If you win with a card, your next card gets -2 damage/power, min 1.
Cripple: SoA. If you win, your next card doesn't have an ability (In this case, you can't just win with 1 card, then throw out a DR or Defeat: + Life card for life gaps).
These card will have slightly higher base Power/Damage than normal, but winning with them will result in a negative effect for your next card.