Kindred Boon

As this enchantment enters, choose a creature type.
{1}{W}: Put a divinity counter on target creature you control of the chosen type.
Each creature you control with a divinity counter on it has indestructible.

The Lost Caverns of Ixalan Commander

As Kindred Boon enters the battlefield, choose a creature type.
{1}{W}: Put a divinity counter on target creature you control of the chosen type.
Each creature you control with a divinity counter on it has indestructible.

The List

Commander 2017

Treasure Chest

If a creature has been dealt damage, that damage remains marked on it until the cleanup step. If a creature with a divinity counter on it has been dealt lethal damage, and later in the turn Kindred Boon leaves the battlefield or the counter is removed from that creature, that creature will be destroyed.

If a creature that isn't of the chosen type somehow gets a divinity counter on it, that creature will have indestructible.

If you somehow control a Kindred Boon with no chosen creature type, its activated ability can't be activated.

You can't choose multiple creature types, such as "Cat Warrior." A Cat Warrior is both a Cat and a Warrior. It's affected by anything that affects either type and unaffected by things that affect non-Cat or non-Warrior creatures.

You must choose an existing creature type, such as Vampire or Cat. Card types such as "artifact" can't be chosen.