Shuriken Arashi and Trick or Treat

[Brocoliviolet]

If I use Shuriken Arashi and my opponent chooses to move to try and get cover behind let's say a size 3 building. If I have powered up Green Goblin ready to blow up that building with Trick or Treat. Does he have the window of opportunity to blow it up before creating the dice pool of Shuriken Arashi, making it a 10 dice attack?

[Thoras]

Yes

Trick or Treat would trigger based on the end of the advance granted by Shuriken Arashi's attack. So when its rule goes to check if the character is benefiting from cover, the terrain is no longer on the battlefield to provide that cover.