Sapping Ritual

When Sapping Ritual enters the battlefield, tap enchanted creature.
Whenever enchanted creature would untap, if it
has a soul counter or a +1/+1 counter on it,
instead remove one of those counters from it and
it doesn't untap. You may place the removed
counter on a permanent you control. When there
are no soul counters or +1/+1 counters on
enchanted creature, sacrifice Sapping Ritual.