// At the beginning of each player's upkeep, that player sacrifices a non-Zombie creature.
Ability ability = new BeginningOfUpkeepTriggeredAbility(new SacrificeEffect(filter, 1, "that player "), TargetController.ANY, false);
this.addAbility(ability);
// At the beginning of the end step, if no creatures are on the battlefield, sacrifice Call to the Grave.
TriggeredAbility triggered = new OnEventTriggeredAbility(GameEvent.EventType.END_TURN_STEP_PRE, "beginning of the end step", true, new SacrificeSourceEffect());
this.addAbility(new ConditionalTriggeredAbility(triggered, new NoCreatureCondition(), ruleText));
}