this.addAbility(FlyingAbility.getInstance());
// Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, it deals X damage to target creature or player, where X is the number of Dragons you control.
DynamicValue dragons = new PermanentsOnBattlefieldCount(filter2);
Ability ability = new EntersBattlefieldAllTriggeredAbility(Zone.BATTLEFIELD, new DamageTargetEffect(dragons), filter, false, rule);
ability.addTarget(new TargetCreatureOrPlayer());
this.addAbility(ability);
// {R}: Scourge of Valkas gets +1/+0 until end of turn.
this.addAbility(new SimpleActivatedAbility(Zone.BATTLEFIELD, new BoostSourceEffect(1, 0, Duration.EndOfTurn), new ManaCostsImpl("{R}")));