Crystal Guardian

The Crystal Guardian is an optional boss in Hollow Knight. The Enraged Guardian is its second, stronger and faster form. Both forms have to be beaten to unlock its Journal entry.

Lore The Crystal Guardian is part of the miners of Crystal Peak who died from the Infection and were reanimated by it. It appears larger than the other husks, has crystal growing on its back and encasing both its arms and its head. It also has more mastery over the crystal's light than the Crystallised Husks.

While encased in crystal, the Guardian shrieks similarly to the Radiance although at a higher pitch. When cleared of the crystal, it has a normal bug voice. Like the other miner husks, it is obsessed with the light but has grown too tired to mine it relentlessly as they do.

In-game events The Guardian is first found on a Bench outside shacks in the middle of the Crystal Peak. It appears dead but prevents the Knight from resting. Striking it wakes it up and starts the fight. If the Knight is defeated and returns, the Guardian has regained its place on the Bench. Upon defeat, the Guardian's crystal growths shatter. Still animated by the Infection, it stands up and escapes by jumping through the ceiling.

The Guardian can be followed to the room above its abandoned resting place using the Monarch Wings. There, it has regained its crystal growths, but its first defeat has made it mad with anger, triggering its second form, the Enraged Guardian. Defeating it a second time breaks its crystal armour again and kills it. This also gives access to a Mask Shard, found within a large crystal deposit.

Behaviour and Tactics The Crystal Guardian has three manoeuvres:
 * Laser Beam: The Crystal Guardian shoots a beam of crystal energy from its hand. It targets the Knight with its arm, firing a beam where they were when it started its attack. The beam is dangerous for about half a second.
 * Sky Beams: The Crystal Guardian screams, and, throughout the arena, up to four beams of crystal energy simultaneously shoot down from the ceiling. These beams each trigger at different times and stay dangerous for about half a second. This attack can happen in conjunction with the Guardian's Laser Beam attack. Each beam can be at a different angle between plus and minus 15 degrees from the vertical.
 * Hop: The Crystal Guardian randomly hops either a short or long distance to move within the arena.

It is possible to defeat the Crystal Guardian before triggering the boss fight by having the Weaversong or Sharp Shadow Charms equipped. This can also be done by repeatedly damaging it with any Spells, though this requires using the Dream Nail on the Crystal Guardian in order to regain SOUL without leaving the room.

The Crystal Guardian telegraphs every beam with a thin beam of light (or multiple in the case of the Sky Beams attack). Pay attention to where the lasers are directed during the Sky Beams attack. A combination of the Sky Beams and Laser Beam attacks limits safe movement the most.

The Desolate Dive/Descending Dark and Vengeful Spirit/Shade Soul Spells are useful. The Howling Wraiths/Abyss Shriek Spell is less useful because the Crystal Guardian is rarely above the Knight. One strategy is to slash at the Guardian with the Nail a few times in between Laser Beam attacks. Another strategy, which is not mutually exclusive to the previous one, is to, during a Laser Beam Attack, jump and dash over the Crystal Guardian to avoid its attack and safely strike it.

Location The Crystal Guardian can be encountered for the first time in the Bench room in the centre of Crystal Peak.

Trivia
 * When standing close to the Crystal Guardian, it sometimes shoots a laser straight into the ground. This is most likely a targeting glitch.
 * Beating the Crystal Guardian in Godhome does not contribute to unlocking its Hunter's Journal entry.
 * Since the Lifeblood update, the Crystal Guardian has a voice when its crystal growth is shattered.
 * Its voice is reused from the Sturdy Fool.

References

Кристаллический страж Guardiano Cristallino Kryształowy Strażnik Gardien de cristal