It depends on how you got the ability. Lemi esplain... no there is too mush. Lemi sum up:
- If they are on a card with charges, they activate only for the effect that triggers the use of the charge
- If they are on a Round Bonus ability card, they are active for the remainder of the round or until you remove the card from the active area
- If they are on a Persistent Bonus ability card, they are active until you remove the card from the active area
- If they are from attack modifier cards or a regular ability card, they are active for the remainder of the round