Sisters of Battle

"Leaders of the Mantis tribe and its finest warriors. They bear thin nail-lances and attack with blinding speed. The Mantis tribe and the bugs of old Hallownest had no love for each other. The Mantises outlived their rivals though, and their civilisation still stands."

The Sisters of Battle are a quest boss in Hollow Knight introduced in Godmaster. First encountered in the Pantheon of Hallownest, they are a form of the Mantis Lords where all three sisters battle together instead of separately.

Behaviour and Tactics
Phase 1 of Sisters of Battle is identical to Phase 1 of Mantis Lords.

In Phase 2, all three Sisters emit a battle cry and drop in to fight. The Sisters of Battle use all attacks of the 2nd Phase of the Mantis Lords, but with an additional attack from a 3rd Sister:
 * Dash & Drop: All three Sisters combine their patterns into fluid combinations. The pattern these attacks follow loosely comes from the patterns of the original Mantis Lords fight. With all three Sisters attacking: two Sisters still follow the patterns of Mantis Lords Phase 2, and one Sister still follows their original pattern like in Mantis Lords Phase 1. The single Sister's attack is staggered to happen just after her two Sisters start their attacks whether it be Drop, Double Drop, Dash or Double Dash. Furthermore, the single Sister's attack will always be a Drop attack if her Sister or Sisters performed Dash attacks. In the case of Drop attacks, it is possible for all three Sisters to choose to chain this attack in quick continuous succession.
 * Boomerang: When all three Sisters are alive, two perform the Boomerang attacks on the wall while the third performs a Drop attack a moment after the spears are thrown. The patterns for the Boomerangs have been modified as well:
 * Two Sisters simultaneously throw their spears creating a wide arc that reaches the opposite end of the arena before coming back together to meet at the centre just at ground level.
 * Two Sisters simultaneously throw their spears creating a short arc that meets in the middle of the arena where they stay locked together while gliding down for a few moments before dispersing apart just above ground level.
 * Two Sisters simultaneously throw their spears: one throwing a wide arc and the other throwing a short arc causing them to meet either of the far ends of the arena and not the centre before dispersing.
 * One Sister throws her spear in either wide or a short arc and leaves while being followed by the Drop attack.
 * The previous Boomerang pattern can be followed up with the other Sister appearing on the opposing wall after the first had finished, and she performs the same pattern.

When two Sisters are left, the Dash and the Drop attacks resume as if it were the Mantis Lords Phase 2, but the Boomerang patterns with the single Sister remain despite the lack of a follow-up Drop attack. The normal "both short" and "both wide" Boomerang patterns occur as regular (this means only the "one short one wide" Boomerang pattern is phased out).

When one Sister remains the fight continues like Mantis Lords Phase 1.

While the Sisters of Battle's attacks are quick and lethal, there are various points in the fight where there is a small window to heal. One major point where healing is possible is at the end of Phase 1 and the transition to Phase 2, where there is a large window of time to heal, as the Sisters of Battle's shout does not stagger the Knight. There are very few other opportunities to heal, so the Quick Focus and Shape of Unn Charms are recommended to make use of the smaller windows of time in-between attacks to heal.

The Shade Cloak is useful for this fight, as the continuous barrage from the Sisters often leads to the Knight getting cornered. The ability to phase through said attacks is practically needed to avoid damage at times.

Jumping and down-striking the Sisters as they pass is a good way to deal damage to them and also re-position to be in a better place to avoid and counter further attacks.

The Vengeful Spirit/Shade Soul Spell is also very helpful to deal damage to the Sisters, as they can move fast, and normal Nail strikes are only 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. Descending Dark/Desolate Dive can also be useful to both deal and possibly negate damage done by the 3 Sisters when they use their Dash & Drop attack.

When the Sisters of Battle use the Boomerang attack, it should be noted that the Dreamshield Charm, if positioned correctly, absorbs the boomerangs, causing the 2 Sisters who threw them to stand still for a few moments. This allows the Knight to get a few hits in before the Sisters commence their next attack.

Location
The Sisters of Battle can first be encountered in the Pantheon of Hallownest, after which they can also be fought in the Hall of Gods. The fight starts off with only a single Sister dropping in to attack: this is used to disguise the fight as the regular Mantis Lords (the title-card for the Mantis Lords is shown, and the Mantis Lords music plays when only fighting one Sister).

Trivia

 * In the Mantis Lords arena in Hallownest, a fourth, broken throne can be seen next to the Mantis Lords' thrones. The arena in Godhome only features three intact thrones, but an unused sprite of the broken throne exists in the game's files.
 * If the Knight continuously clings to the wall, one Sister will continue to use the Boomerang attack on the opposite side of the arena until the Knight leaves the wall. The boomerang is directed specifically to hit the Knight.
 * In Phase 2, all three Sisters actively throw boomerangs on the opposing wall.
 * In the second phase, the Sister on the right will always be defeated first, then the left, then the middle, no matter which Sister is actually defeated.