Glass Shielding

Enchant Creature
Prevent all damage that would be dealt to
enchanted creature. When you prevent 2 or more
damage, add a Shatter counter to Glass Shielding.
When enchanted creature becomes target by a
spell or ability, counter that spell or ability.
Then add a Shatter counter to Glass Shielding.
At the beginning of each upkeep, if there are 4 or
more Shatter counters on Glass Shielding
sacrifice it.