// Mana Vault doesn't untap during your untap step.
this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new SkipUntapSourceEffect()));
// At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
this.addAbility(new BeginningOfUpkeepTriggeredAbility(
Zone.BATTLEFIELD,
new DoIfCostPaid(new UntapSourceEffect(), new GenericManaCost(4)),
TargetController.YOU,
false));
// At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
this.addAbility(new ConditionalTriggeredAbility(
new BeginningOfDrawTriggeredAbility(Zone.BATTLEFIELD, new DamageControllerEffect(1), TargetController.YOU, false),