Water Barrier

Casualty X (As you cast this spell, you may
sacrifice a creature with power X or greater.
When you do, copy this spell and you may
choose new targets for the copy.)
Put a shield counter on each of up to X
target creatures. (If a creature with a shield
counter would be dealt damage or destroyed,
remove a shield counter from it instead.)
Artwork source:
https://www.artstation.com/artwork/bdbbo