Sanctuary Warden

Flying
Sanctuary Warden enters with two shield counters on it.
Whenever Sanctuary Warden enters or attacks, you may remove a counter from a creature or planeswalker you control. If you do, draw a card and create a 1/1 green and white Citizen creature token.

Streets of New Capenna

Flying
Sanctuary Warden enters the battlefield with two shield counters on it.
Whenever Sanctuary Warden enters the battlefield or attacks, you may remove a counter from a creature or planeswalker you control. If you do, draw a card and create a 1/1 green and white Citizen creature token.

Streets of New Capenna Promos

A creature with a shield counter on it may still be destroyed by state-based actions if it has damage marked on it equal to its toughness or has been dealt unpreventable damage by a source with deathtouch.

If a permanent that would be dealt damage has more than one shield counter on it, that damage is prevented and only one shield counter is removed.

If a permanent with a shield counter is dealt unpreventable damage, that damage will be dealt and a shield counter will still be removed.

Removing a shield counter in this way isn't the same as regenerating a creature.

Sanctuary Warden's triggered ability allows you to remove any kind of counter, not just a shield counter.

Shield counters don't prevent players from sacrificing creatures.

“Shield” is not an ability that creatures have and shield counters are not keyword counters. If a creature with a shield counter loses its abilities, the shield counter will still protect it as normal.