Soul Trap

Whenever a creature dies, put 1 counter on Soul
Trap.
{1}, Remove 1 counter from Soul Trap: Deal 1
damage to target creature.
Soul-traps can vary in appearance, jewelled
rune-etched skulls or pyramid-shaped prisms for
example, but all have the same function - to allow
their wielder to capture the soul of a particularly
powerful foe and use the stolen energies to boost his or
her strength.