Shadow Dragon Arts, Dividing Shadows (X-BT04/0050EN) (X-BT04)

[Cast Cost] [Put any number of souls from a "Shadow Dragon" on your field into the drop zone]
[Counter] Choose cards on your opponent's field up to the number of cards put into the drop zone by this card's [Cast Cost], and destroy the chosen cards. You gain life, and deal damage to your opponent, equal to the number of cards destroyed!