How to unlock Cavern of Corrosion in Honkai: Star Rail

Honkai Star Rail In The Sweltering Morning Sun Serval And Gepard Closeup
Screenshot by PC Invasion

Honkai: Star Rail continues introducing stages and farming destinations until well into its campaign. One such destination is the Cavern of Corrosion, where you can acquire precious relics you’ll need for character growth. Here is our guide on how to unlock the Cavern of Corrosion in Honkai: Star Rail.

Honkai: Star Rail – How to unlock Cavern of Corrosion

Once it’s available, the Cavern of Corrosion is a destination you can visit from the Survival Index in the Interastral Guide. It includes a number of rare Relics, including pieces of the Passerby of Wandering Cloud set. To unlock Cavern of Corrosion in Honkai: Star Rail, you must make your way through multiple sub-missions in a Trailblaze mission called In the Sweltering Morning Sun.

It heavily involves two characters: Serval and Gepard. You’ll find it near the end of your journey through the snow-covered planet of Jarilo-VI. You can’t tackle the mission until your Trailblaze level reaches 24. Then you can access the Cleanse in the Darkness Outside sub-mission and proceed from there.

Honkai Star Rail Cavern Of Corrosion Discovering Entrance
Screenshot by PC Invasion

Cleanse in the Darkness Outside mostly consists of a lot of talking. Next, you will proceed to the Unattainable Idol sub-mission. You must deal with numerous Silvermane Guard enemies on your way to a boss battle with Gepard. The soldiers tend to fare poorly against wind attacks, which Dan Heng uses efficiently. Lightning magic is also effective against area mobs, which Serval uses very well. If you have a character that deals quantum damage (though I didn’t), that also will hit enemy weaknesses.

Honkai Star Rail Unattainable Idol Sub Mission Gepard Battle
Screenshot by PC Invasion

Gepard himself is weak against lightning, physical, and imaginary attacks. You need to focus on healing and protecting your characters, especially if you have Serval in your party. Her lightning attacks are useful, especially since Gepard periodically calls for backup. My party composition was Serval, Dan Heng, Bailu, and March 7th. I recommend a similar setup if you have those characters available. March 7th produces nice barriers for your healer and for Serval, in that case, plus her ultimate move freezes mobs that might otherwise get bad ideas.

Related: All Navigation Compass puzzle solutions in Honkai: Star Rail

Once you defeat Gepard, the Soldiers Stay Silent sub-mission begins. It kicks off with a three-wave battle against some moderately powerful foes. After the discussion that follows that conflict, you’ll automatically begin The Stars Are Cold Toys.

Clearing The Stars Are Cold Toys requires you to activate all mechanisms in the Corridor of Fading Echoes area. As you begin working to complete that task, you soon turn a large gear counter-clockwise one time to negotiate a wide pit at the center of the area. Cross along the repositioned gear and start along the next balcony it allows you to access. You’ll reveal a portal that leads to the Cavern of Corrosion. Activate it so you can revisit it at your leisure. Each run consumes 40 Trailblaze Power.

All Relic rewards from the Cavern of Corrosion in Honkai: Star Rail

You’ll want to check out the Cavern of Corrosion often, since it offers excellent Relics to add to your characters’ builds. There are two different Relic sets offered from each Cavern of Corrosion, so let’s explore which ones you can get and who they’re perfect for.

Cavern of Corrosion NameLocationRelic Set rewardsBest characters
Path of ConflagrationStargazer Navalia, Xianzhou Luofu– Firesmith of Lava Foraging
– Wastelander of Banditry Desert
– Hook, Himeko
– Welt, Imbibitor Lunae, Yukong
Path of DriftingCorridor of Fading Echoes, Jarilo-VI– Passeryby of Wandering Cloud
– Musketeer of Wild Wheat
– Natasha, Bailu, Luocha
– Pela, Yukong, Trailblazer
Path of Elixir SeekersAlchemy Commission, Xianzhou Luofu– Longevous Disciple
– Messenger Traversing Hackerspace
– Blade, Natasha, Arlan, Clara
– Bronya, Asta, Tingyun
Path of Gelid WindStorage Zone, Herta Space Station– Hunter of Glacial Forest
– Eagle of Twilight Line
– Yanqing, Herta
– Dan Heng, Sampo, Blade
Path of Holy HymnCloudford, Xianzhou Luofu– Knight of Purity Palace
– Band of Sizzling Thunder
– March 7th, Gepard, Trailblazer (Fire)
– Serval, Kafka, Jing Yuan, Arlan
Path of Jabbing PunchSilvermane Guard Restricted Zone, Jarilo-VI– Champion of Streetwise Boxing
– Thief of Shooting Meteor
– Trailblazer, Clara, Luka, Sushang
– Welt, Asta
Path of ProvidenceEverwinter Hill, Jarilo-VI– Guard of Wuthering Snow
– Genius of Brilliant Stars
– Gepard, Trailblazer (Fire)
– Seele, Qingque, Silver Wolf

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Honkai: Star Rail is available on PC and PS5.

Jason Venter
About The Author
Jason Venter is a contributing writer for PC Invasion since 2022 who can trace his love for video games back to the Apple IIe port of Mario Bros. in the late 80s. He remains a diehard Nintendo fan to this day and loves JRPGs, adventure games, and platformers in particular, but he still plays games in most genres and on most hardware. After founding indie gaming site HonestGamers in 1998, he served as an editor at Hardcore Gamer Magazine during its entire print run. He has since freelanced for a variety of leading sites including IGN, GameSpot, and Polygon. These days, he spends most of his time writing game guides and entertaining readers with his fantasy novels.