// {1}, {tap}, Sacrifice Gremlin Mine: Gremlin Mine deals 4 damage to target artifact creature.
Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new DamageTargetEffect(4), new ManaCostsImpl("{1}"));
ability.addCost(new TapSourceCost());
ability.addCost(new SacrificeSourceCost());
ability.addTarget(new TargetArtifactPermanent(filterCreature));
this.addAbility(ability);
// {1}, {tap}, Sacrifice Gremlin Mine: Remove up to four charge counters from target noncreature artifact.
ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new GremlinMineEffect(), new ManaCostsImpl("{1}"));
ability.addCost(new TapSourceCost());
ability.addCost(new SacrificeSourceCost());
ability.addTarget(new TargetArtifactPermanent(filterNonCreature));
this.addAbility(ability);
}