Abyss Watchers
Maximum souls: 267,688
From the Crucifixion Woods bonfire, sprint to the ladder that takes you to Farron Keep. Two knights would stand near the ladder to harass you. If you don't want them to harass you, get to the ladder as quickly as possible, descend the ladder a bit, and wait for them to fall to their death. Another strategy is to cast Hidden Body when you're on the shore of the swamp and then sprint to the ladder. Light the Farron Keep bonfire. Two-hand a dagger and weapon art your way across the swamp of Farron Keep to diffuse the 3 fires. Cast Hidden Body if you want. Refer to the following video for the strategy.
Defuse the Farron Keep 3 fire, Dark Souls III
The Abyss Watchers are weak against fire and lightning. Here are some strategies to fight them, assuming that you first cast Sacred Oath or use the weapon art of the Sunlight Straight Sword, and cast Deep Protection:
- Equip a Pyromancy Flame+10, attune Chaos Bed Vestiges, and equip these rings: Lloyd's Sword Ring, Witch's Ring, Great Swamp Ring. The fourth ring can be any you want. If you want high risk and high reward, equip the Fire Clutch Ring. If you want fast Stamina regeneration, equip the Chloranthy Ring+3. Then spam Vestiges in the boss' face.
The Abyss Watchers can be staggered with a 2-handed R1 of an ultra great sword. For example, 2-hand a Fume Ultra Greatsword+5 and buff it with Carthus Flame Arc. An R1 suffices to stagger the boss. If you want, you can perform a fully charged thrust R2 to stun lock the boss. See the following video for the strategy.
Two-hand a Lothric Knight Greatsword+10 and use Yorshka's Chime+10 to buff it with Lightning Blade. Equip these rings for extra damage output: Lloyd's Sword Ring, Lightning Clutch Ring. At the start of the first phase, wait for the boss to charge at you with his weapon and look for an opportunity to backstab him. Proceed to perform a 2-handed fully charged thrust R2 to stun lock the boss to death. Use the same strategy during the second phase. Of all the ultra great swords having a 2-handed thrust R2, the Lothric Knight Greatsword has the highest damage output while the Fume Ultra Greatsword has the longest reach. The next video demonstrates the strategy using the Lothric Knight Greatsword.
Abyss Watchers NG+32 Lothric Knight Greatsword, Dark Souls III
Summon an NPC and use any of the above strategies. In Embered state, you can summon either Black Hand Gotthard or Londor Pale Shade. Depending on how far you progress with Anri and Sirris' quest lines, you can summon Anri. If you play online and use the Dried Finger, you can summon a second NPC phantom to help you.