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 - $7.70
Moderately Played - $6.30
Heavily Played - $2.30
Damaged - $0.90
Near Mint Reverse Holofoil - $25.00
Lightly Played Reverse Holofoil - $21.30
Moderately Played Reverse Holofoil - $17.50
Heavily Played Reverse Holofoil - $6.30
Damaged Reverse Holofoil - $2.50