My bf and I were having an argument whether or not we take damage from Mystical defenses if we already have an environment card out. I said that the card at the end of the turn, generally doing 2 energy damage, does not affect us because I think “non-environment targets” are cards unaffected by the environment card (with another environment card in play). He thinks that “non-environment targets” means that it gives damage to everyone and it only doesn’t effect an environment with hp.
Thoughts?
The non-environment targets are everyone that is not an environment card, so both Heros and Villian cards take the damage. So say you have your four hereos out going against rand Warlord Voss and he has three minions out and the Kraken is also out. The four heroes, Grand Warlord Voss, and his three minions would all take damage seeing as none are enironment targets. Kraken would be uninjured considering the fact that it is a environment target.
Hope this helped.
The latter interpretation is correct. Non-environment targets are hero targets and villain targets, so everything except the environment cards with HP.
I can second (third?) the statements made by Ronway and WriterRyan 
Also, just to clarify:
Any card with HP is a “target”. A “villain target” is any target from the villain deck, or the villain character card itself. A “hero target” is any target from a hero deck, or a hero character card. And an “environment target” is any target from an environment deck.
With respect to environments, generally speaking, any number of environment cards can be in play at the same time, and their effects all still apply (so you can get into terrible situations where there are 3 krakens and 2 mystical defenses going off every turn. Of course, vigilance in taking care of environment cards as they are played can avoid this situation