Xylesha, Demonic Nullmancer

Dark Mastery (This creature deals damage to
creatures in the form of dark counters, if a creature has
more dark counters than its toughness, exile it)
At the beginning of your upkeep, reveal the top
card of your library and put that card into your
hand. You lose life equal to its converted mana
cost.
When the light she held to so dearly betrayed her, she embraced the empty darkness.