I'm assuming the Bloodboil Fever card should be "Forced" instead of an "Action"?

Attach to a target unit.
Action: At the beginning of its controller's turn, put a resource token on this card. Then, deal X damage to the attached unit. X is the number of resource tokens on this card.

The action allow more choice for the player of this card, the forced effect would be less good.

Remember that the controler of this card is the person that own the card by default so in most of case the person which have played this card, not the person which control the unit with this card.

comicthoughts said:

Yeah, the fact that it says "put a resource token on" rather than "may put a resource token on" is just because the templating is poor. All Actions are "may" despite the fact that only half of them say it.