Obtain covenant rewards
Farming for covenant items can be tedious. However, some covenants reward you with various spells that are required to unlock certain Steam achievements. Start farming for covenant items before proceeding to the next NG cycle. Farm the target enemies until they no longer respawn, at which point you might want to burn a Bonfire Ascetic to revive them or wait until the next NG cycle to farm the same enemies again. Equip these to boost your item discovery: Jester's Cap, Prisoner's Tatters, Watchdragon Parma, Covetous Gold Serpent Ring(+0, +1, +2). Pop a Rusted Coin before you start a farming round. It is mandatory to rank up in the following covenants to unlock certain Steam achievements: Bell Keepers, Heirs of the Sun, Pilgrims of Dark. Below are some covenant items you might want to farm.
Obtain all covenant rewards from the Bell Keepers covenant. Join the covenant and play offline to prevent PvP. Clear Iron Keep of all enemies and use the Unveil miracle by the Belfry Sol Approach bonfire to help you determine whether the Mad Warrior spawns. After defeating the Mad Warrior 30 times, exhaust the dialogue of the Belfry Guard and be rewarded with the Hidden Weapon sorcery. Levelling up in the Bell Keepers covenant is the only way to obtain this sorcery. You must collect all sorceries to unlock a Steam achievement. This video has more details:
Rank up in the Rat King covenant either through PvP or farm Rat Tail x 35 by killing rats at the Grave of Saints. Give the Rat Tail x 35 to the Rat King to receive all covenant rewards. None of the covenant rewards are required to unlock a Steam achievement.
Ranking up in the Heirs of the Sun covenant is the only way to obtain all covenant rewards. You need the Sunlight Spear miracle to unlock a Steam achievement. Farm Sunlight Medal x 30 either through jolly co-operation by helping hosts defeat bosses or by farming the Falconers. Falconers are found at these locations:
Near the Ruined Fork Road bonfire, on the path to Drangleic Castle.
- Near the Royal Army Campsite bonfire, at Brightstone Cove Tseldora.
From NG+1 onward, Falconers are found near your initial spawn point at Things Betwixt.
Rank up in the Company of Champions covenant to obtain all rewards. Upon reaching rank 1, you would be rewarded with Great Magic Weapon, a sorcery that can be purchased from Royal Sorcerer Navlaan or collected at the Black Gulch. You don't need to rank up in this covenant to unlock a Steam achievement. Refer to the section Grave of Saints for how to farm Awestones.
- All rewards from the Blue Sentinels, Way of Blue, and Brotherhood of Blood covenants can be obtained through other means. You don't need to join these covenants and PvP in order to obtain all rewards. Purchase all items from Blue Sentinel Targray and then defeat him to obtain his Blue Knight's Halberd. Purchase all items from Titchy Gren and then defeat him to obtain the Nahr Alma Hood. The Nahr Alma Robes and the Scythe of Nahr Alma can both be purchased from Melentia. Refer to the section Grave of Saints for how to increase your rank in the Way of Blue covenant.
- Rank up in the Dragon Remnants covenant to obtain all rewards. You require Dragon Scale x 30, which can be farmed through PvP or from defeating the Dragon Warriors at Dragon Shrine. The Dragon Warriors can be tough to fight because they tend to gank you. Dragon Scales can also be farmed from The Imperfect at Shulva, Sanctum City. None of the covenant rewards are required to unlock a Steam achievement. Refer to the sections Dragon Shrine and Shulva, Sanctum City for how to farm Dragon Scales.
- Exhaust the dialogue of Darkdiver Grandahl at these locations: Shaded Woods, Black Gulch, and Drangleic Castle. Then join the Pilgrims of Dark covenant. Clear all three Dark Chasms of Old and defeat Darklurker to receive all covenant rewards. The hex Climax can only be obtained after reaching rank 3 in the covenant. You require all hexes to unlock a Steam achievement. Refer to the section Darklurker for how to increase your rank in the Pilgrims of Dark covenant.