When using the Bard skill cards, when is the fatigue spent? When the song token is placed on the card, or each time the card takes effect?

Also, can both song tokens be on one skill card, or does it have to be one or the other?

Lastly, once a token is placed on a bard skill card, does it need to remain there until the end of the encounter, or can it be removed and placed on a different card each turn?

Thank you in advance for any insights!

Fatigue is spent when the token is placed on the card. Both tokens can be on the same card. It can be swapped to another card whenever you are able to activate the new card, for the fatigue cost of the new card.

Thank you, Whitewing!

Token also stays on until end of encounter unless moved.

Token also stays on until end of encounter unless moved.

Even if the bard is knocked down the token stays, but while he;s out the ability isn't active.