Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new MagosiTheWaterveilEffect(), new ManaCostsImpl("{U}"));
ability.addCost(new TapSourceCost());
this.addAbility(ability);
// {tap}, Remove an eon counter from Magosi, the Waterveil and return it to its owner's hand: Take an extra turn after this one.
Ability ability2 = new SimpleActivatedAbility(Zone.BATTLEFIELD, new AddExtraTurnControllerEffect(), new TapSourceCost());
ability2.addCost(new RemoveCountersSourceCost(CounterType.EON.createInstance()));
ability2.addCost(new ReturnToHandSourceCost());
this.addAbility(ability2);
}