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 - $9.00
Lightly Played - $8.10
Moderately Played - $6.70
Heavily Played - $4.50
Damaged - $0.90
Near Mint Reverse Holofoil - $29.00
Lightly Played Reverse Holofoil - $26.10
Moderately Played Reverse Holofoil - $21.80
Heavily Played Reverse Holofoil - $14.50
Damaged Reverse Holofoil - $2.90