// Whenever a creature dealt damage by Repentant Vampire this turn dies, put a +1/+1 counter on Repentant Vampire.
this.addAbility(new DiesAndDealtDamageThisTurnTriggeredAbility(new AddCountersSourceEffect(CounterType.P1P1.createInstance()), false));
// Threshold - As long as seven or more cards are in your graveyard, Repentant Vampire is white and has "{tap}: Destroy target black creature."
Ability ability = new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinousEffect(
new SetCardColorSourceEffect(ObjectColor.WHITE, Duration.WhileOnBattlefield),
new CardsInControllerGraveCondition(7),
"<i>Threshold</i> - As long as seven or more cards are in your graveyard, {this} is white"));
Ability gainedAbility = new SimpleActivatedAbility(Zone.BATTLEFIELD, new DestroyTargetEffect(), new TapSourceCost());
gainedAbility.addTarget(new TargetCreaturePermanent(filter));
ability.addEffect(new ConditionalContinousEffect(
new GainAbilitySourceEffect(gainedAbility, Duration.WhileOnBattlefield),
new CardsInControllerGraveCondition(7),
"and has \"{t}: Destroy target black creature.\""));
this.addAbility(ability);
}