HoYoverse announced that Honkai: Star Rail's Version 1.6, “Crown of the Mundane and Divine”, will arrive on December 27. The forthcoming update will unveil a fresh area: the Herta Space Station's Seclusion Zone, previously inaccessible until Madam Ruan Mei, one of the members of the Genius Society, initiated her groundbreaking biological science experiments within its confines. Accompanying this expansion are new playable characters: Madam Ruan Mei, Dr. Ratio, and Xueyi, along with the reunion of two old friends, Blade and Kafka. More importantly, once version 1.6's "Panta Rhei" event warp starts, every trailblazer who has unlocked the mail feature shall receive one limited five-star character Dr. Ratio.

After helping out with the Paranormal crisis on Fyxestroll Garden, the Trailblazer will return to Herta Space Station and encounter Madam Ruan Mei for the first time. In the process of clone cultivation, Madam Ruan Mei did encounter a certain anomaly, which showed up in the form of a Swarm King prototype and a fierce Swarm Disaster entity. Due to an incident during the experiment, this "Borehole Planet's Old Crater" came into being in the Seclusion Zone of Herta Space Station, where Trailblazer will be stuck in a tough fight.

In addition, version 1.6 will embrace a brand-new DLC of the Simulated Universe: Gold and Gears, where Ruan Mei has developed a simulated Nous and frozen space-time just before the demise of member 27 — Emperor Rubert. This latest update adds the Path of Erudition and daringly experiments with separating dice from paths. The dice come with six slots for equipping various Dice Face effects. By collecting Trailblaze Secrets, the Trailblazer can unlock even more Dice Face effects while facing different challenges.

To accelerate research developments aboard the space station, the Trailblazer has been entrusted with a vital mission: fostering and tending to the newly arrived small and cute lifeforms. Through the Critter Pick Scavenging event, the Trailblazer can select nurturing objectives outlined in the manual and acquire cultivation techniques to raise an assortment of charming little creatures! Furthermore, version 1.6 will introduce numerous gameplay improvements, including the incorporation of Pure Fiction, additional stages in the Forgotten Hall, and various other user-friendly updates.

Three new characters will join the player’s roster to facilitate the grand space expedition, including Madam Ruan Mei, Dr. Ratio, and Xueyi. To start with, Madam Ruan Mei is a 5-star Ice-Type character following the Path of Harmony, and member 81 of the Genius Society. From the very beginning, her research has focused on biological science. Despite being one of the founders of the Simulated Universe, she seldom steps up to the plate. Her Skill, Strings Sing in Slow Twirls, can increase damage and Weakness Break’s efficiency of all allies. Ruan Mei has a knack for exploiting an enemy's Weakness and great support for the Break Effect dealt by allies.

Another scholar called Dr. Ratio will also make his debut. He is a 5-star Imaginary-Type character following the Path of the Hunt, belonging to a different Nous-worshiping organization — the Intelligentsia Guild. As a rigorous academic researcher, Dr. Ratio pays close attention to his enemies' debuffs during battle. The more debuffs the enemy has, the higher the chance of him launching a follow-up attack.

The last new character is Xueyi, a 4-star Quantum-Type character following the Path of Destruction, whose original body was replaced long ago with a permanent puppet system. This system was constructed for Xueyi on behalf of the Ten-Lords Commission. The Commission agreed that for every culprit Xueyi apprehended, she would be rewarded with a half day's wakespan. Like her sister Hanya, Xueyi is a formidable presence on the battlefield. Her Ultimate, Divine Castigation, can deal Quantum DMG to a single target and Toughness depletion that ignores Weakness Types. The more Toughness depleted, the greater the DMG!