How often (and when) do variable powers, such as Tempest’s Shielding Winds, check the variable?
So, for example, Tempest puts out Shielding Winds with two other weather cards (let’s say one of them is Thunderclap) in play, so the damage taken by hero targets is now -3.
In an effort to finish off another villain target, Tachyon or Wraith destroys the Thunderclap to get damage done to a target. Does Shielding Winds now only offer -2 to damage taken, or is the damage resistance buff fixed when playing the card?
Likewise, I know Nightmist (RCR) has an ongoing card (I don’t remember the name off the top of my head, sorry) that has both an effect when it is played and during NM’s next start phase based on the top card of her trash. Is it checked when resolving, or upon initial play only?
I’m not seeing anything in the rulebook that says one way or another, but it is entirely possible I’m just missing it.
Thanks!