Isaac himself is now immune to all damage, and a heart familiar appears and follows Isaac. If the heart is hurt, Isaac is hurt.
Quote
"Protect It"
Effects
Isaac's body becomes immune to all damage.
A heart familiar appears and closely follows Isaac. If the heart is hurt, Isaac is hurt.
The heart tries to position itself in the opposite direction of where Isaac is shooting.
The heart charges up as Isaac fires. At full charge, upon releasing the fire button, it knocks back nearby enemies and tears, creates a small puddle of red creep on the ground, and releases blood shots in 8 directions.
Enemies that come in contact with Isaac take 7 damage over 2-3 ticks per second.
Enemies still target Isaac.
Synergies
Box of Friends - Box of Friends does not duplicate the heart, making it safe to use.