Optional: Curse-Rotted Greatwood

Maximum souls: 133,537

This boss is weak against fire. Although the boss is a gimmick fight where you must burst the various sacs, aiming fireballs at the sacs can result in the fight being more difficult than it should be. An easy strategy is to 2-hand a weapon that has an R1 vertical swing to allow you to easily hit the sacs. Consider using a Sunlight Straight Sword+5 and buff the weapon with Carthus Flame Arc. Cast Sacred Oath and Deep Protection and equip these rings for extra damage output: Witch's Ring, Great Swamp Ring.

Before triggering the fight, use some kind of ranged weapon to dispatch of all enemies who are praying in front of the boss, thus making the boss fight itself less annoying than it should be. In the 1st phase, burst the sacs on the boss' left hand and left leg, followed by the sacs on its abdomen. If you are quick enough, you should now be able to cast Sacred Oath and re-apply Carthus Flame Arc before the 2nd phase begins. In the 2nd phase, burst the sacs behind the boss near its left bum cheek. Then burst the sacs on the boss' right leg and finally R1 the pale arm protruding from the boss' abdomen. In the 2nd phase, you can once again burst the sacs on the boss' abdomen, but this strategy is dangerous because the protruding arm would slam or grab you. The video below demonstrates the strategy.

Curse-Rotted Greatwood NG+32 Sunlight Straight Sword, Dark Souls III