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 - $7.70
Lightly Played - $6.90
Moderately Played - $5.80
Heavily Played - $3.90
Damaged - $0.80
Near Mint Reverse Holofoil - $14.10
Lightly Played Reverse Holofoil - $12.70
Moderately Played Reverse Holofoil - $10.60
Heavily Played Reverse Holofoil - $7.10
Damaged Reverse Holofoil - $1.50