Lifeblood

For the in-game mechanic of "Lifeblood" see Lifeblood Cocoon

Lifeblood is the third free content pack to Hollow Knight, following The Grimm Troupe on 26 October, 2017. It was officially released on 20 April, 2018, after a period in public beta. Lifeblood was originally arranged to be just a major update, but in all later instances and mentions it has been referred to as a content pack. It is followed by Godmaster released on the 23rd of August, 2018.

As it was not one of the three originally planned content packs, it did not release with a teaser. Lifeblood focused mainly on enhancing technical aspects of the game, bringing upgrades and optimizations of various kinds.

Changes

Main menu

Players became able to change the background of the title screen (Extras section). The menu styles include:

Classic (Unlocked from start)
Hidden Dreams ( Hidden Dreams update)
Grimm Troupe ( The Grimm Troupe update)
Lifeblood (Lifeblood update)
Infected (Unlocked by beating The Hollow Knight)
Void (Unlocked by beating The Radiance)
Steel Soul (Unlocked by completing Steel Soul Mode, any ending)

Two more with the

Godmaster update:

Godmaster (Godmaster update)
The Eternal Ordeal (Unlocked by getting 57 kills in The Eternal Ordeal)

And one last one with Voidheart Edition:

Voidheart (Included in Voidheart Edition)

A changelog was added to the Extras section in the main menu, which includes information about every major version of the game
Blur quality can be changed through the Video menu

Visual Changes

The Hive area gained a complete visual redesign
The Zote statue implemented in the Hidden Dreams update now only has four candles, but will still turn gold after ten defeats
Animation for travelling the stagways is longer and now able to be skipped
Parallax is a lot smoother and clearer
Using Crystal Heart Dash now gives off a flash of purple light (the animation may also be quicker)
Tram pass slots now have a glowing yellow light
Calling and riding the Tram now has a rippling overlay effect
New room transitions have been implemented
The Knight now has a new burst animation when taking damage
Damage taken from coming in contact with spikes triggers a unique burst animation
Damage taken that deals multiple masks now triggers a new burst animation
- This animation can be seen when the Knight is killed
Dying in Steel Soul Mode has a unique animation
Decorative mushrooms in the foreground of Fungal Wastes now react to the Knight walking over them and let out a puff of spores
The arena for the Lost Kin loses saturation and is more greyscale
There are now three unique GIFs for loading screens: normal, dream and the Colosseum of Fools
New icon for getting an achievement
"Infected" blood physics and sprites have been modified
Modified effects for getting Shade Cloak
A red barrier now appears when the player uses a spell in the secret room in Grimm's Tent

Enemy Changes

Hivelings are now much larger and have more Hp
Traitor Lord gained two new attacks, now deals two masks of damage and is a lot faster
- Traitor Lord has a visual cloud of orange Infection surrounding him
The Hollow Knight's diving flame pillar attack now does two masks of damage
The Collector can now be staggered
Nightmare King Grimm is now only accessible while wearing the Grimmchild charm
Some Warrior Dreams had contrast and colour tweaks
Hive Guardians do two masks of damage
Volatile Mosskin explode faster upon death
Desolate Diving onto Flukemarm no longer functions
Husk Hive is larger, faster and can spawn Hivelings with only a short pause
False Knight's stagger animation is faster
Fungified Husk's spore cloud is significantly bigger
The bodies of the Watcher Knights have been rearranged
Belflys will leave their skull behind after death, when they die by themselves it will still count towards the Hunter's Journal
Lifeblood Cocoons now contain a fixed number of Lifeseeds

NPC Changes

The Dung Defender now has extra dialogue after the player beats the White Defender five times
- If the player encounters the new dialogue from the Dung Defender and then re-enters his home, a dung statue of the Knight can be found next to the others.
Divine now has extra dialogue when the player talks to her while wearing the Defender's Crest (added for a misconception)
Dreamer sequence after the Hornet Protector fight in Greenpath has new animations
New dialogue and animation for Hive Queen Vespa once the Hive Knight has been defeated
Bretta's previously added dialogue now coincides with the number of candles lit on the Zote statue, she will also run away after four defeats of Grey Prince Zote

Charm Changes

Flukenest's damage has been nerfed and now costs 3 notches
Weaversong's Weaverlings do more damage (up from 2 to 3) with a new attack animation and can stagger bosses
- Weaversong and Sprintmaster have a new interaction which causes the Weaverlings to move faster, wander a bit farther from the player and jump higher
- Weaversong and Grubsong now have a new interaction which causes damaged Weaverlings to give the player soul
Joni's Blessing now only grants 40% + 1 more HP (down from 50% + 1).
Fury of the Fallen's activated effects has a new design and instead of a red circle highlighting the player, the player now emits a red smoke
New animation for when Grimmchild attacks Millibelle

Audio Changes

Fungoons have a new attack sound
Bluggsacs have an idle sound
Fool Eaters have a new attack sound
Mosscreeps have a new spawn sound
Siblings have a new sound when they spawn
Crystallised Husks have a new attack sound
Wingmoulds have a new sound when they are struck
Shrumal Warriors have a new death sound
Shrumal Ogres have a new death sound
Shrumelings have a new sound for when they pop up and run away
Volatile Mosskin have new attack and death sound
Mosskin have a new attack and death sound
Moss Knights have new attack and death sound
Gulkas have a new death sound
Mistakes have a new death sound
Sporgs have a new sound when they pop out to attack
Glimbacks have a new and louder scuttling sound whilst patrolling
New sound for placing a Dream Gate in an invalid location
Dreamshield makes a new sound when it passes over a piece of Geo
Dung Defender and White Defender now audibly pounds his chest when he transitions
Sound for when spikes are revealed at the beginning of the fight with Mantis Lords has been changed
Different audio volume levels for arena/wave-styled fights in City of Tears
New sound for breaking mushroom flora in Fungal Wastes
New sound for breakable pipes and such in Royal Waterways
Bretta is now audibly scared when first finding her