How to use

setText

method

in

mage.abilities.effects.common.continuous.BecomesCreatureSourceEffect

public BecomesCreatureSourceEffect(Token token, String theyAreStillType, Duration duration, boolean losePreviousTypes, boolean characterDefining, DynamicValue power, DynamicValue toughness, boolean loseAbilities) {
  super(duration, Outcome.BecomeCreature);
  this.characterDefining = characterDefining;
  this.token = token;
  this.theyAreStillType = theyAreStillType;
  this.losePreviousTypes = losePreviousTypes;
  this.power = power;
  this.toughness = toughness;this.loseAbilities=loseAbilities;
  setText();
  this.addDependencyType(DependencyType.BecomeCreature);
}

public AngelsTomb(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.ARTIFACT}, "{3}");
  // Whenever a creature enters the battlefield under your control, you may have Angel's Tomb become a 3/3 white Angel artifact creature with flying until end of turn.
  Effect effect = new BecomesCreatureSourceEffect(new CreatureToken(3, 3, "3/3 white Angel artifact creature with flying")
      .withColor("W")
      .withSubType(SubType.ANGEL)
      .withAbility(FlyingAbility.getInstance()),
      "", Duration.EndOfTurn)
      .setText("have {this} become a 3/3 white Angel artifact creature with flying until end of turn");
  this.addAbility(new EntersBattlefieldControlledTriggeredAbility(
      Zone.BATTLEFIELD,
      effect,
      StaticFilters.FILTER_PERMANENT_CREATURE_A,
      true)
  );
}

public ChromiumTheMutable(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{4}{W}{U}{B}");
  this.addSuperType(SuperType.LEGENDARY);
  this.subtype.add(SubType.ELDER);
  this.subtype.add(SubType.DRAGON);
  this.power = new MageInt(7);
  this.toughness = new MageInt(7);
  // Flash
  this.addAbility(FlashAbility.getInstance());
  // This spell can't be countered.
  this.addAbility(new CantBeCounteredAbility());
  // Flying
  this.addAbility(FlyingAbility.getInstance());
  // Discard a card: Until end of turn, Chromium, the Mutable becomes a Human with base power and toughness 1/1, loses all abilities, and gains hexproof. It can't be blocked this turn.
  Ability ability = new SimpleActivatedAbility(
      new BecomesCreatureSourceEffect(
          new ChromiumTheMutableToken(), null, Duration.EndOfTurn,
          false, false, null, null, true
      ).setText("Until end of turn, {this} becomes "
          + "a Human with base power and toughness 1/1, "
          + "loses all abilities, and gains hexproof."),
      new DiscardCardCost()
  );
  ability.addEffect(
      new CantBeBlockedSourceEffect(Duration.EndOfTurn)
          .setText("It can't be blocked this turn.")
  );
  this.addAbility(ability);
}