Sisters of Battle

The Sisters of Battle is a quest boss in Hollow Knight introduced in Godmaster. They are a form of the Mantis Lords where all three sisters battle together instead of separately.

Behaviour and Tactics
The Shade Cloak is extremely useful for this fight, as the continuous barrage from the Lords often leads to the player getting cornered. The ability to phase through said attacks is practically needed to avoid damage at times.

Jumping and Nail-striking the Lords as they pass is an excellent way to deal damage to them and also reposition to be in a better place to avoid and counter further attacks.

Vengeful Spirit /Shade Soul is also very helpful to deal damage to the Lords, as they can move fast and normal Nail strikes will only be able to hit them a few times before they retreat. As such, these ranged spells are good to catch one of them during the short recovery window after an attack.

Location
The Sisters of Battle can be first encountered in the Pantheon of Hallownest, after which they can also be fought in the Hall of Gods. The fight will start off with only a single Sister dropping in to attack: this is used to catch the player off guard and disguise the fight as regular Mantis Lords (even the Mantis Lords namecard will show and the Mantis Lords OST will play when only fighting one Sister).

Trivia

 * If the player continuously clings to the wall, one Mantis Lord will continue to use the Boomerang attack on the opposite side of the arena until the player leaves the wall. The boomerang will be directed specifically to hit the Knight.
 * In Phase 2, all three lords will all be actively throwing boomerangs on the opposing wall.