Constella Tiara

Instant -

, destroy this: Prevent the next 1 damage that would be dealt to you this turn. If you prevent damage this way, create a Ponder token.

When Constella Tiara’s instant activated ability resolves, it generates a shielding-prevention effect that prevents the next 1 arcane damage that would be dealt to your hero this turn. When applying the shielding-prevention effect, if you prevent any damage this way (e.g. reduce the amount of damage being dealt by the event), you will create a Ponder token. Neither player receives priority between applying/reducing the damage being dealt and creating the token.
This prevents all types of damage including damage from attacks ( damage), arcane damage, and (untyped) damage. This does not prevent loss of life.