How to use

CastWithoutPayingManaCostEffect

in

mage.abilities.effects.common.cost

  @Override
  public CastWithoutPayingManaCostEffect copy() {
    return new CastWithoutPayingManaCostEffect(this);
  }
}

public YahennisExpertise(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.SORCERY}, "{2}{B}{B}");
  // All creatures get -3/-3 until end of turn.
  this.getSpellAbility().addEffect(new BoostAllEffect(-3, -3, Duration.EndOfTurn));
  // You may cast a card with converted mana cost 3 or less from your hand without paying its mana cost.
  this.getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(3));
}

public RishkarsExpertise(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.SORCERY}, "{4}{G}{G}");
  // Draw cards equal to the greatest power among creatures you control.
  Effect effect = new DrawCardSourceControllerEffect(GreatestPowerAmongControlledCreaturesValue.instance);
  effect.setText("Draw cards equal to the greatest power among creatures you control");
  this.getSpellAbility().addEffect(effect);
  // You may cast a card with converted mana cost 5 or less from your hand without paying its mana cost.
  this.getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(5));
}

public SramsExpertise(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.SORCERY}, "{2}{W}{W}");
  // Create three 1/1 colorless Servo artifact creature tokens.
  this.getSpellAbility().addEffect(new CreateTokenEffect(new ServoToken(), 3));
  // You may cast a card with converted mana cost 3 or less from your hand without paying its mana cost.
  this.getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(3));
}

public BaralsExpertise(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.SORCERY}, "{3}{U}{U}");
  // Return up to three target artifacts and/or creatures to their owners' hands.
  getSpellAbility().addEffect(new ReturnToHandTargetEffect());
  getSpellAbility().addTarget(new TargetPermanent(0, 3, filter, false));
  // You may cast a card with converted mana cost 4 or less from your hand without paying its mana cost.
  getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(4));
}

public Electrodominance(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.INSTANT}, "{X}{R}{R}");
  // Electrodominance deals X damage to any target. You may cast a card with converted mana cost X or less from your hand without paying its mana cost.
  this.getSpellAbility().addEffect(new DamageTargetEffect(ManacostVariableValue.instance));
  this.getSpellAbility().addTarget(new TargetAnyTarget());
  this.getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(ManacostVariableValue.instance));
}

public KariZevsExpertise(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.SORCERY}, "{1}{R}{R}");
  // Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
  this.getSpellAbility().addTarget(new TargetPermanent(filter));
  this.getSpellAbility().addEffect(new GainControlTargetEffect(Duration.EndOfTurn));
  this.getSpellAbility().addEffect(new UntapTargetEffect().setText("Untap it"));
  this.getSpellAbility().addEffect(new GainAbilityTargetEffect(HasteAbility.getInstance(), Duration.EndOfTurn).setText("It gans haste until end of turn."));
  // You may cast a card with converted mana cost 2 or less from your hand without paying its mana cost.
  this.getSpellAbility().addEffect(new CastWithoutPayingManaCostEffect(2));
}