Genshin Impact Leak Reveals Ambitious New UGC Sandbox Mode: "Miliastra"

A significant new leak has unveiled details about Genshin Impact’s upcoming user-generated content (UGC) mode, which promises to be one of HoYoverse’s boldest expansions yet. Codenamed “Thousand Stars” or “Miliastra,” the new game mode will empower players to design custom characters, build interactive experiences, and join social lobbies with up to 20 players—a major shift from the game's traditional format.

🛠️ Miliastra: Genshin’s New Creative Frontier

According to trusted leaker Mero, Miliastra will function as a standalone sandbox mode, separate from the main Genshin launcher—but sharing the same game assets. This means it won’t require significantly more storage, making it accessible to most players.

Miliastra is set to feature a full suite of UGC tools, allowing players to:

• Create their own custom character, with full options for clothing, skin tone, facial features, and more.
• Engage in creative world-building, including puzzle maps, combat arenas, and roleplay settings.
• Host public lobbies (up to 20 players) or private lobbies (up to 12 players) for social and co-op play.

Initial beta tests only allow female avatars, but a male model will be added in time for full release.

🎨 Customization, Cosmetics & Monetization

Miliastra will introduce a new gacha system, not for characters, but for cosmetics and outfits. It will also come with its own Battle Pass, separate from the main game’s system. According to early leaks, players can earn or wish for cosmetic gear—but some items may be locked behind Primogem-only purchases, raising concerns about paywalls.

The sandbox will also use its own currency system, along with a stamina mechanic similar to Resin, but with a larger cap to accommodate broader gameplay.

🗺️ A Lore-Inspired World: Ties to Simulanka and Alice?

Leaked footage of Miliastra’s lobby reveals visual inspiration from Simulanka, the whimsical location from Genshin’s Version 4.8 Summer Event. The lore and design suggest a possible connection to Alice, Klee’s mother and an enigmatic figure in Teyvat’s lore, who may be behind this "creative dimension."

In Miliastra, players can explore player-built adventures, from parkour challenges to narrative-driven quests—making it Genshin’s most versatile mode to date.

🔮 Community Reaction & Release Window

While community impressions have been largely positive, concerns remain over potential aggressive monetization. Still, many fans are excited about the social and creative potential of the mode.

Miliastra is reportedly in the final stages of development, with further details expected soon as beta testing continues. A full release date has yet to be confirmed.