Spawns an orbital familiar that blocks enemy shots and deals 7 damage per tick or 105 damage per second on contact ( 53 damage per second).
It also attracts enemy shots to itself, making them more likely to be blocked. A shot actively being attracted can no longer damage Isaac and is essentially nullified, but if it slips outside the Protector's range, it can again deal damage.
Sworn Protector has a chance to drop an Eternal Heart upon blocking 10 shots in one room.
This can only happen once per room, but leaving and re-entering a room will allow another eternal heart to be dropped.
This item belongs to the Seraphim set. Collecting three items from this set will transform Isaac into an angel.
This item belongs to the Conjoined set. Collecting three items from this set will transform Isaac into a three-faced version of himself.
Notes
Sworn Protector can be exploited with the help of a Constant Stone Shooter to spawn unlimited eternal hearts.
Synergies
Friendly enemies: Spawning a friendly enemy that shoots bullets allows Eternal Hearts to be farmed since the friendly enemy will fire at Isaac if no hostile enemies are in the room.
Extension Cord: Familiar and Isaac are occasionally connected by electricity, but it is very hard to notice because Sworn Protector orbits so close to Isaac.
Friendly enemies: Friendly enemy tears are ignored by Sworn Protector.
53 damage per second).
Eternal Heart upon blocking 10 shots in one room.
This item belongs to the 
Seraphim set. Collecting three items from this set will transform Isaac into an angel.
Conjoined set. Collecting three items from this set will transform Isaac into a three-faced version of himself.
Constant Stone Shooter to spawn unlimited eternal hearts.
Sacrificial Altar: This familiar will also reward 2 
Black Hearts when sacrificed.
Extension Cord: Familiar and Isaac are occasionally connected by electricity, but it is very hard to notice because Sworn Protector orbits so close to Isaac.
Uriel/ 
Gabriel.
Best Bud.
The Lost Unlocks 
Hush Unlocks 
The Binding of Isaac: Rebirth
