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 - $6.65
Near Mint Reverse Holofoil - $14.10
Lightly Played - $6.30
Lightly Played Reverse Holofoil - $13.40
Moderately Played - $5.65
Moderately Played Reverse Holofoil - $12.00
Heavily Played - $5.00
Heavily Played Reverse Holofoil - $10.55
Damaged - $4.65
Damaged Reverse Holofoil - $9.85