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)
Can I use Umbreon-GX's "Dark Call GX" attack to discard 2 Double Colorless Energy?
Yes, you can select 1 Energy of each Double Colorless Energy to discard both of them. This applies for discarding your own Energy for an attack and for retreating as well. So if you used Hoopa-EX's "Hyperspace Fury" attack or paid its Retreat Cost of 2, discarding 2 Double Colorless Energy would be legal options.
Source: TPCi Rules Team (2017-01-26), TPCi Rules Team (2017-06-27)
Say my opponent used Turtonator GX's "Shell Trap" attack last turn, then on my turn I attack it with Tapu Bulu GX's "Tapu Wilderness GX" attack. Does "Shell Trap" place its damage counters before or after the healing part of "Tapu Wilderness GX"?
Tapu Wilderness GX heals Tapu Bulu GX as part of its attack before the damage counters are placed for Shell Trap's effect. So in the end Tapu Bulu GX will have 8 damage counters on it.
Source: TPCi Rules Team (2017-06-08)
Say my opponent used Turtonator GX's "Shell Trap" attack last turn, then on my turn I attack it with Shaymin EX's "Sky Return" attack. What happens to the 8 damage counters effect from "Shell Trap"?
Sky Return puts Shaymin EX into the hand as part of its attack before the damage counters are placed for Shell Trap's effect.
Source: TPCi Rules Team (2017-06-08)
If Vileplume's "Allergy Panic" Ability is in effect, does Rayquaza's "Shred" attack consider a Defending Pokemon's weakness as x2 or x4?
Shred isn't affected by "any effects on the Defending Pokemon", but the term "any effects" does not include effects that alter Weakness or Resistance. So in this case the Defending Pokemon's Weakness would be x4 due to Allergy Panic.
Source: TPCi Rules Team (2013-02-28), TPCi Rules Changes Announcement (2017-05-03), TPCi Rules Changes Announcement (2017-05-18)
What happens if I have less than three spaces on my bench when using Politoed's "Roll Call" attack? Or what if I don't have any room on my bench at all?
You can use the attack no matter how many Pokemon are on your Bench, but you can only get as many Pokemon as you have spaces on your Bench.
Source: Guardians Rising FAQ (2017-04-22), TPCi Rules Team (2017-05-04)