If my opponent has Ampharos with "Electromagnetic Wall" in play, when I attach a Double Colorless Energy to one of my Pokemon, do I place 3 or 6 damage counters?
You place 3 because there was only one attachment, even though the attachment provided multiple energies.
Source: TPCi Rules Team (2012-09-13)
Would Emboar's "Inferno Fandango" Ability trigger Ampharos' "Electromagnetic Wall" Ability? Or does "Electromagnetic Wall" only apply to the opponent's normal once-per-turn energy attachment?
Any energies attached from the hand would trigger Electromagnetic Wall, regardless of whether they're attached due to an Ability or the normal once-per-turn energy attachment.
Source: TPCi Rules Team (2012-09-13)
Would the two Basic energy cards attached by Terrakion EX's "Pump-up Smash" attack trigger Ampharos' "Electromagnetic Wall" Ability twice or only once (or not at all)?
Any energies attached from the hand would trigger Electromagnetic Wall, once for each energy card being attached.
Source: Dragons Exalted FAQ (2012-08-23), TPCi Rules Team (2012-08-23)