After defeating the Old Dragonslayer in the Blue Cathedral, you can access the balcony beyond the chapel. Out here is Blue Sentinel Targray. Speak to him with a Token of Fidelity in your inventory, and he'll offer to let you join the Blue Sentinels.
The Blue Sentinels are all about protecting others. Members can be summoned into a world currently being invaded, with the goal of killing the invader to protect the host. They can also used Cracked Blue Eye Orbs to invade worlds of players who successfully invaded and killed a host. In addition, they can use the statues by the Cathedral of Blue bonfire to enter exhibition matches with other players.
- Rank 1: Win 50 exhibition matches or defeat 50 invaders.
- Reward: Spirit Tree Shield
- Rank 2: Win 150 exhibition matches or defeat 150 invaders.
- Reward: Wrath of the Gods
- Rank 3: Win 500 exhibition matches or defeat 500 invaders.
- Reward: Bountiful Sunlight