If the Pokemon Darkness Energy is attached to does damage with an attack (after applying Weakness and Resistance), the attack does 10 more damage. At the end of every turn, put 1 damage counter on the Pokemon Darkness Energy is attached to, unless it's D or has Dark in its name. Darkness Energy provides D Energy. (Doesn't count as a basic Energy card.)
Near Mint - $5.80
Near Mint Reverse Holofoil - $14.70
Lightly Played - $5.50
Lightly Played Reverse Holofoil - $14.00
Moderately Played - $4.95
Moderately Played Reverse Holofoil - $12.50
Heavily Played - $4.35
Heavily Played Reverse Holofoil - $11.05
Damaged - $4.05
Damaged Reverse Holofoil - $10.30