Burning Hunting the Quarry

Name: Hunting the Quarry
[SV5:PCaine6]
Cardtype: Combat
Path: Caine
Discipline: Celerity/Thaumaturgy
Only usable if both combatants are still ready. A vampire can play only one Hunting the Quarry each combat.
[cel] or [tha] Only usable if combat is about to end. Put this card on the opposing minion. You still control this card. Vampires you control can burn this card to attempt to enter combat with the attached minion as a +1 stealth action.
[CEL] or [THA] Only usable if combat would end. Instead, this vampire burns 1 blood to start a new round.
Artist: Michele Bertilorenzi

emime wrote:

Name: Hunting the Quarry
[SV5:PCaine6]
Cardtype: Combat
Path: Caine
Discipline: Celerity/Thaumaturgy
Only usable if both combatants are still ready. A vampire can play only one Hunting the Quarry each combat.
[cel] or [tha] Only usable if combat is about to end. Put this card on the opposing minion. You still control this card. Vampires you control can burn this card to attempt to enter combat with the attached minion as a +1 stealth action.
[CEL] or [THA] Only usable if combat would end. Instead, this vampire burns 1 blood to start a new round.
Artist: Michele Bertilorenzi

Inferior Hunting the Quarry is written in a way that makes me a bit confused, with that "vampires" in the plural and the "burn to attempt" formulation.

Is burning the card the cost of the action (hence, not payed if it is unsuccessful), or the card needs to be burned anyway to attempt the action, whether successful or not? Thank you!

... Strike with Conviction:

If the action to bleed with Strike with Conviction is blocked, Strike with Conviction isn’t burned. The action it provides is to burn it and bleed (none of which happens if the action is blocked). ...

Name: Strike with Conviction
[NoR:C]
Cardtype: Conviction
Burn to make a hand or weapon strike against a monster at +1 damage.
Burn to bleed at +1 bleed as a (D) action.
Artist: Mark Poole

emime wrote:

I started from the same point of view, but was put out of balance (after a discussion on the Italian chat) by the “burn to attempt” wording: if it were “burn to enter combat” I would have no doubt that it is a cost. Like this, hmmm… still doubting.