// Whenever a spell or ability you control counters a spell, you may put a 1/1 blue Merfolk creature token onto the battlefield.
this.addAbility(new LullmageMentorTriggeredAbility());
this.addWatcher(new CastedSpellsWithSpellTarget());
// Tap seven untapped Merfolk you control: Counter target spell.
Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new CounterTargetEffect(), new TapTargetCost(new TargetControlledCreaturePermanent(7, 7, filter, true)));
ability.addTarget(new TargetSpell());
this.addAbility(ability);
}