How to use

LoseHalfLifeTargetEffect

in

mage.abilities.effects.common

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

public HavocFestival(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.ENCHANTMENT}, "{4}{B}{R}");
  // Players can't gain life.
  this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new CantGainLifeAllEffect()));
  // At the beginning of each player's upkeep, that player loses half their life, rounded up.
  this.addAbility(new BeginningOfUpkeepTriggeredAbility(Zone.BATTLEFIELD, new LoseHalfLifeTargetEffect(), TargetController.ANY, false));
}

public VirtusTheVeiled(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{B}");
  this.addSuperType(SuperType.LEGENDARY);
  this.subtype.add(SubType.AZRA);
  this.subtype.add(SubType.ASSASSIN);
  this.power = new MageInt(1);
  this.toughness = new MageInt(1);
  // Partner with Gorm the Great (When this creature enters the battlefield, target player may put Gorm into their hand from their library, then shuffle.)
  this.addAbility(new PartnerWithAbility("Gorm the Great", true));
  // Deathtouch
  this.addAbility(DeathtouchAbility.getInstance());
  // Whenever Virtus the Veiled deals combat damage to a player, that player loses half their life, rounded up.
  this.addAbility(new DealsCombatDamageToAPlayerTriggeredAbility(new LoseHalfLifeTargetEffect(), false, true));
}

public QuietusSpike(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.ARTIFACT}, "{3}");
  this.subtype.add(SubType.EQUIPMENT);
  // Equipped creature has deathtouch.
  this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new GainAbilityAttachedEffect(DeathtouchAbility.getInstance(), AttachmentType.EQUIPMENT)));
  // Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
  this.addAbility(new DealsDamageToAPlayerAttachedTriggeredAbility(new LoseHalfLifeTargetEffect(), "equipped", false, true));
  // Equip {3}
  this.addAbility(new EquipAbility(Outcome.AddAbility, new GenericManaCost(3)));
}

public Scytheclaw(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.ARTIFACT}, "{5}");
  this.subtype.add(SubType.EQUIPMENT);
  // Living weapon
  this.addAbility(new LivingWeaponAbility());
  // Equipped creature gets +1/+1.
  this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new BoostEquippedEffect(1, 1)));
  // Whenever equipped creature deals combat damage to a player, that player loses half of their life, round up.
  this.addAbility(new DealsDamageToAPlayerAttachedTriggeredAbility(new LoseHalfLifeTargetEffect(), "equipped", false, true));
  // Equip {3}
  this.addAbility(new EquipAbility(Outcome.AddAbility, new GenericManaCost(3)));
}

public EbonbladeReaper(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{B}");
  this.subtype.add(SubType.HUMAN);
  this.subtype.add(SubType.CLERIC);
  this.power = new MageInt(1);
  this.toughness = new MageInt(1);
  //Whenever Ebonblade Reaper attacks, you lose half your life, rounded up.
  this.addAbility(new AttacksTriggeredAbility(new LoseHalfLifeEffect(), false));
  //Whenever Ebonblade Reaper deals combat damage to a player, that player loses half their life, rounded up.
  this.addAbility(new DealsCombatDamageToAPlayerTriggeredAbility(new LoseHalfLifeTargetEffect(), false, true));
  //Morph {3}{B}{B}
  this.addAbility(new MorphAbility(this, new ManaCostsImpl<>("{3}{B}{B}")));
}