Abilities » Eternal Zone
If I have an Eternatus VMAX with "Eternal Zone" Ability and less than 8 Pokemon (all Darkness type) on my bench, can I use Giratina's "Distortion Door" Ability to put it from the discard pile onto my bench and use its effect before it is discarded?
No, you cannot even put it onto your bench because it is a non-Darkness Pokemon.
Source: Darkness Ablaze FAQ (2020-07-31), TPCi Rules Team (2020-08-13)
Abilities » Eternal Zone
Can a dual-type Pokemon like Bisharp from Steam Siege (being both a Darkness type and Metal type) be played onto the bench while Eternatus VMAX's "Eternal Zone" ability is on?
Yes, as long as the Pokemon is Darkness type it can be played onto the bench.
Source: TPCi Rules Team (2020-08-13)
Abilities » Eternal Zone | Attacks » Time Spiral
If I have Eternatus VMAX with "Eternal Zone" Ability in play and my opponent uses Celebi's "Time Spiral" attack to devolve one of my benched Darkness type Pokemon to a non-Darkness type Pokemon with enough damage already on the devolved Pokemon to knock it out, is it KO'd before having to reduce my Bench down to 5 Pokemon, or if I discard it to reduce my bench is it not KO'd?
You would discard your Bench down to 5 first, then check for a KO. That means you could discard the newly devolved Pokemon to avoid a KO, even if Eternatus VMAX is the one being devolved!
Source: TPCi Rules Team (2020-08-13)
Abilities » Darkness Guard
If I use Rhyperior V's "Drill Run" attack against a Darkrai with "Darkness Guard" Ability and only one Darkness Energy card attached, does Darkrai take 20 less damage before discarding the Darkness Energy or is the energy card discarded before the damage is reduced?
If an attack discards energy from the Defending Pokemon, the damage reduction happens first and then apply any attack effects.
Source: Darkness Ablaze FAQ (2020-07-31), TPCi Rules Team (2020-08-13)
Abilities » Dark Asset
If I play Crobat V to the bench and use its "Dark Asset" Ability, can I use Super Scoop Up to bring it back to my hand then put it down to use "Dark Asset" again on the same turn?
Sorry, but the ability says that you may use ONLY ONE Dark Asset per turn, this applies regardless of whether any other Pokemon have used it.
Source: Darkness Ablaze FAQ (2020-07-31), TPCi Rules Team (2020-08-13)
Attacks » Mining Rush
When using Diggersby's "Mining Rush" attack, can I discard cards one at a time or do I have to discard them all at once?
You may discard cards one by one for Mining Rush and stop any time before you reach the maximum amount specified in the attack. You do not have to declare up front how many cards you're going to discard.
Source: TPCi Rules Team (2020-05-07)
Attacks » Counter
Does Cinderace VMAX's "Counter" attack do extra damage if Cinderace VMAX goes to the Bench and then returns to the Active Slot?
It doesn't matter where Cinderace VMAX was when it was damaged during your opponent's last turn, nor whether it has switched in or out of the Active Slot. If it was damaged by an attack during your opponent's last turn Counter will do that much more damage. This is not an effect to be removed when the Pokemon goes to the bench. Counter is performing a game state check asking if something happened; since it did, it uses that game state information to calculate how much damage Counter will do.
Source: TPCi Rules Team (2020-05-07)
Attacks » Call for Family
Am I allowed to use Gossifleur's "Call for Family" attack if my Bench is already full?
You can use the attack, but since it's public knowledge that you can't put any Pokemon onto your Bench the entire effect of the attack fails; you can't even search your deck.
Source: Supreme Victors FAQ (2009-08-27), PUI Rules Team (2009-08-27), PUI Rules Team (2020-05-07)