The Bell Keepers are a pvp and invasion-themed Covenant in Dark Souls 2. Upon joining the covenant the player will be given a Bell Keeper's Seal ring, and five Rusted Coins after talking to the dwarf.

Belfry Luna Dwarf
Belfry Luna/ Belfry Sol

1. Kill other players invading Belfry Luna/Belfry Sol
2. Farm offline NPC, which is the way I'm gonna tell you about. :)

- It's red phantom. You will farm him in Belfry Sol.
1. He has really low chance to spawn, so for this strategy you will need to get miracle called Unveil. It can be bought from Straid for 2200 souls. (He is near the bonfire with petrified statue called Straid's Cell. You will get here from Servants' Quarters Bonfire).
2. You need to clear all the Dwarves in Belfry Luna and Archer, which is near the bonfire (You will see him when going up the ladder).
3. After having those 2 steps done, it's very simple. You will rest at the bonfire and cast Unveil spell. When the spell will fly up to your character, Mad Warrior didn't spawn. When the miracle will fly away from you and go through ceiling, Mad Warrior spawned. If he spawned, go up and kill him. If he didn't, rest at bonfire and try again.

This method will save you a lot of time, because you don't need to get up the ladder every time.

-> Defeat him 10 times, than talk to Dwarf (You will get Titanite Slab as a reward).
-> Defeat him 30 times, than talk to Dwarf again (You will get Hidden Weapon, which is Sorcery required to get Achievement for getting all Sorceries).
-> Defeat him 100 times (You will obtain Bell Keepers Set).

TIP: He has really small chance of spawn, but chance can be higher using Bonfire Astetics.

Thanks for reading, it's my first guide ever, so I hope it will at least help somebody. Feel free to comment, Like & Fav would make me happy. Enjoy your beautiful day! :)