Radiance

Behaviour and Tactics
The Radiance is the true final boss of Hollow Knight. To access her, the player must have acquired Void Heart and have used the Dream Nail on the Hollow Knight when Hornet holds them down to be able to challenge her.

In the first phase of the fight, she levitates slightly above the floor. Only her body is vulnerable to attack, which requires jumping or ranged attacks. She will often teleport around, making it even harder to get a good string of hits in while avoiding her own ruthless attacks.

The Radiance does not deal contact damage, however, most of her attacks except summoning spikes will deal two masks damage upon hit. Falling off the platform will also only do one mask of damage.



Charm Sets

Ill Advised

Quick Slash: Exchanges with The Radiance will be air-borne (until the fourth phase), so spam openings that Quick Slash excels with are non-existent.

Long Nail/Mark of Pride: There is no contact damage and most of The Radiance's attacks are stage centric instead of from her body, so the spacing advantage these charms offer are of little use here.

Recommended

Occasions to hit The Radiance are limited, and her attacks deal 2 masks of damage, as such you will likely face high damage with limited SOUL. Most successful builds will be centered around preserving/increasing resources or removing the need for them.

Quick Focus and Deep Focus work well with each other, as Deep Focus allows you to recover more health with less SOUL and Quick Focus ensures that you can safely perform the heal.

SOUL-generation charms like Soul Catcher and Grubsong are also suggested. Fragile Strength can be a lifesaver by increasing damage output tremendously. However, the Radiance does not count as a "Dream boss" and deaths to her will break Fragile charms. To prevent the Charm from breaking, pause the game and reload if you believe you are about to die, or upgrade to Unbreakable Strength.

It should be noted that in the first three phases, the swordbeams from Grubberfly's Elegy can be used to hit The Radiance without jumping, which can be especially useful when combined with Quick Slash.

Joni's Blessing and Lifeblood Heart/Core can be useful for those finding it hard to heal.

A spell-focused build can be employed by forgoing any healing Charms for the Lifeblood charms described above along with Shaman Stone, allowing the player to spam Abyss Shriek to get quick and easy damage off, as the Radiance does not get knocked back and will take all four hits of the Spell.

Phase Breakdown

In general, panic heals are more costly here than in other fights; as SOUL is limited and damage intake is high for mistakes. So avoid it!

In Phase 1 There is ample time when The Radiance is spawning, so use this to your advantage by spamming jump+UpSlash or magic. From here, The Radiance will use her attacks one after the other with ample time between, all while hovering above the floor and teleporting. The hardest attacks to avoid are typically the horizontal walls of swords and the homing projectiles. And as the attacks interval shrinks, you will need to be mindful of Shadow Dash cool-down for Wall of Light. With proper timing and spacing, all attacks (save homing spheres) are good opportunities for healing, though the safest options are third salvo of the eye beam and a break in Spike Wall where the next wave requires no jump to avoid.

In Phase 2, The Radiance continues using the same attacks, but will now create spikes across alternating halves of the platform. The restrained space makes it much harder to maneuver and to stall out the cooldown of the Shadow Dash. She will switch the location of the spikes every 5 seconds, outlining their new location with a golden glow for about 2 seconds as a warning before they actually emerge. Be sure to use the warning and not panic; take your time to avoid any in-progress attack before moving to safe ground. These spikes also only deal one mask of damage, so if you must choose between these and other attacks, let yourself hit the spiked grounds.

In Phase 3, The Radiance will float in the center of the platform, place spikes at the edges and endlessly rain down swords from above. This is generally not a good time to heal as the spikes come down in fairly short intervals. It is better to get through the phase as there is ample time before phase 3 starts to heal.

In Phase 4, The Radiance resumes using all of her normal attacks, but she is now fought on a field of small platforms over the Void. To the player's advantage, they can gain a lot more distance from The Radiance to heal, as all attacks have a lot more ground to cover before reaching The Knight. Wall of Light is an especially good opportunity to heal, as you will hear the attack's sound when it is off screen, letting you know well ahead of time to heal before it gets to you. Though when it comes to approaching The Radiance for the offense, you will need to be smart: if she is off screen when she is prepping her next attack, you will have limited time to react appropriately, often being caught mid jump by an unexpected attack. In this case you are much better off maintaining distance and waiting for the next opening.

The last phase, Phase 5, involves ascending by jumping up platforms as The Radiance flees again. Her only attack in this phase is the Big Beam. Upon reaching the Radiance, hit her one more time with the Nail to end the fight and trigger the final sequence.

In the final sequence, The Radiance is bound by Void Tendrils and the shade of the Hollow Knight appears, tearing open a weak point on her face. The Knight bursts out of their body and becomes their Shade. Attacking causes the Shade to repeatedly whip The Radiance's weak point with long tendrils until it's defeated and dragged into the Void below.

Trivia

 * Beating the Radiance is not required to complete the Hunter's Journal, but she does have an entry.
 * There is a statue of The Radiance at the top of the map in Hallownest's Crown where a Pale Ore can be found. Dreamnailing this statue will yield the lines
 * "...Remember... Light..."


 * Through HUD manipulation, The Radiance is shown to actually have 3000 health, though the "fight" portion of the battle ends when she reaches 1300 health, effectively requiring the player to only have to deal 1700 damage to win the fight.
 * Along with Nightmare King Grimm, The Radiance is the only boss that has a fullscreen title card.
 * The Radiance is confirmed to be female from developer commentary on Slack, as well as from developer notes regarding the Seer:
 * The moth tribe were (perhaps) descended from Radiance. However, the King convinced them somehow to seal Radiance away. I guess so he could rule Hallownest with his singular vision, as a monarch/god with no other gods.The moths sealed Radiance away by forgetting about her. Hallownest was born and flourished. However, the memory of Radiance lingered (eg the statue at hallownest's crown) and soon she began to reappear in dreams and starting exerting influence. The King and the bugs of hallownest resisted this memory/power and it started to manifest as the infection. Thus the first attempt to seal Radiance failed, and the King had to try another method - the Vessel.


 * The Radiance is one of the two bosses that must be challenged to battle, the other being the Mantis Lords. While the Mantis Lords will have to be challenged every time, the Radiance's intro is abridged after the first time fighting it, causing her to attack directly upon entering her arena.
 * The Design of The Radiance appears to be based off a Silkworm moth
 * The Radiance being called "Light" could be a reference to real life moths, as they are attracted to light sources.

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