When facing multiple adversaries during the encounter phase, are vorpal powers cumulative or do we need to face each adversary separately?
For example, I have both a bored succubus (1 fight, 1 skill, 8 charm) and a skeletal warrior (2 fight) on my tower ring. Can I discard a total of 3 fight, 1 skill and 8 charm to defeat them both simultaneously?
Can the rule be applied to other cards in the tower levels as well?
I guess it would depend on the cards played. As long as none of the fight, skill or charm came from the same card(s) that provided the 2 fight to defeat the skeletal warrior or the 2 fight does not come from the cards used to defeat the succubus.
In the 'questions' section, page 23 it is asked:
Q: Can I split the power value on a card toward two or more separate cards?
A: No. A card's power value must be spent entirely toward a single card. Any left over power (i.e. "overspent") is lost.
Also, any Vorpal on a single card has to be used as a single power type. This is asked and answered on the same page, the very next question.
I think these answer your question.