Does Seviper's "More Poison" Ability stack with the effect of Toxapex GX's "Super Intense Poison" attack?
Yes, you first put 10 damage counters for the Super Intense Poison attack and then you get to add 1 damage counter for each More Poison ability.
Source: TPCi Rules Team (2017-08-03)
If my opponent used Turtonator GX's "Shell Trap" attack and I have Magearna EX with the "Mystic Heart" Ability in play, will my Pokemon with Metal energy attached get the 8 damage counters from "Shell Trap" if I attack and do damage to Turtonator GX?
No, it will not receive the 8 damage counters. Mystic Heart prevents all effects of your opponent's attacks, and Shell Trap's damage counters are an effect of your opponent's attack.
Source: TPCi Rules Team (2017-08-03)
If I use Bruxish's "Synchronoise" attack against my opponent's dual type Pokemon like Volcanion EX, and there are other Volcanion EX on the Bench, do they take 40 damage or 20?
They take 20 damage.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
If my opponent has no Benched Pokemon, can I still use Alolan Muk-GX's "Tri Hazard-GX" attack?
You can use it, but it won't have any effect, and it will count as having used your GX attack for the game.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
If I use Araquanid's "Bubble Net" attack and my opponent switches in a new Active Pokemon, can they attach an Energy to it during their turn?
Yes they can. The effect was on that specific Defending Pokemon and was removed when it went to the Bench.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
If I use Palossand's "Dust Storm" attack against a Stage 2 Pokemon, do I discard the Basic and Stage 1 cards attached to the Stage 2 Pokemon?
No. The Basic and Stage 1 as well as the Sandygast are part of their respective Pokemon and are not discarded.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
If I put a Charizard GX in play using Ho Oh GX's "Eternal Flame GX" attack, and my opponent evolves into Porygon-Z and uses its "Initialize" Ability, does Charizard GX go back into my hand?
No. Charizard GX is in play as an "unevolved Pokemon" and so is not affected by the Ability.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
If I use Ho-Oh GX's "Eternal Flame GX" attack, can I place a Stage 2 Pokemon like Charizard GX from my discard pile directly onto my Bench?
Yes. The attack does not specify that the selected Pokemon have to be Basic Pokemon.
Source: Burning Shadows FAQ (2017-07-20), TPCi Rules Team (2017-08-03)
When using Drampa GX's "Berserk" attack, must ALL Benched Pokemon have at least 1 damage counter or do you only need 1 Benched Pokemon with a damage counter on it to add the +70 damage?
If any of your Benched Pokemon have damage counters it will add the +70 damage. If it required all of them it would have said "all" or "each" in the attack text.
Source: TPCi Rules Team (2017-07-06)
Does Umbreon GX's "Dark Call GX" attack have to discard 2 energy from a single Pokemon, or can I discard 1 energy from two separate Pokemon? Or does it mean to discard 2 energy from each of my opponent's Pokemon??
The term "Pokemon" in the attack is plural, but it doesn't mean all of your opponent's Pokemon. You may discard 2 energy from one Pokemon, or you may discard 1 energy each from two Pokemon.
Source: TPCi Rules Team (2017-01-26), TPCi Rules Team (2017-06-27)