this.addAbility(new SimpleActivatedAbility(Zone.BATTLEFIELD, new AddCountersSourceEffect(CounterType.DEVOTION.createInstance()),new TapSourceCost()));
// {T}: Target creature gets -X/-X until end of turn, where X is the number of devotion counters on Bloodthirsty Ogre. Activate this ability only if you control a Demon.
DynamicValue devotionCounters = new SignInversionDynamicValue(new CountersCount(CounterType.DEVOTION));
Ability ability;
ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new BoostTargetEffect(devotionCounters,devotionCounters, Duration.EndOfTurn, true),new TapSourceCost());
ability.addCost(new ControlPermanentCost(filter));
ability.addTarget(new TargetCreaturePermanent());
this.addAbility(ability);
}