It's not just fan speculation; Genshin Impact and Honkai Impact 3rd are canonically connected. Regarding a Honkai Impact character named Fallen Rosemary, the developer has cited Dvalin as something observed in another world via the Imaginary Tree in Chapter 17. But there are many more subtle elements that could connect the two stories as well.
Honkai Impact 3rd is miHoYo's other flagship title, also a gacha game. Like Genshin Impact, which has branched out into the visual novel and open-world genres, Honkai also incorporates many gameplay types such as social simulation and dungeon crawling, while maintaining itself as primarily a gacha game. And like Genshin, Honkai features a deep lore that continues to unfold, but its main premise is that an alternate version of Earth is being threatened by a mysterious chaos, or honkai in Chinese.
Confirmed Connections Between Genshin and Honkai Impact
Other than confirming Dvalin's existence in Honkai Impact's universe, the clearest indication of connections lies within the two names.
It's easy to notice that the two names share the same word "impact." While this may seem minute, it's worth pointing out that this could mean that the stories relate to the same series. None of miHoYo's other games use the word "impact," though some are also gachas, including Guns GirlZ. However, many do share an antagonist, namely the Herrscher of the Void.
But the name Impact also holds significance to Honkai's universe. In short, Herrschers attempt to destroy humanity in apocalyptic events sometimes referred to as "impacts." This could imply that Genshin's story is leading up to an Impact by the Herrschers in this universe. But this, along with much other speculation, has yet to be confirmed by in-game lore.
Unconfirmed Speculation Relating Genshin and Honkai Impact
Off the bat, the opening of Genshin Impact states that the Traveler fell in Teyvat from another world after battling with an unknown god. But it's also known that Overseer Otto observes other worlds in Honkai Impact's Chapter 17 of the main story, including Dvalin. Via the Imaginary Tree, it's confirmed there's a canon method of connecting the two worlds, at least through observation if not by traveling to them as well. Before arriving in Teyvat, the twins were traveling to different worlds, but it's not said where they came from before one is shunted 500 years into the future.
The Unknown God that the twins fight at the beginning of Genshin Impact is also the center point of fan theories that the two games are connected. Her design is eerily similar to that of the Herrscher of the Void in Honkai Impact, the main villain of the game, including in her glowing yellow eyes, her long white hair, and the dark tendrils that extend from her dress. Herrscher of the Void has the ability to summon dimensional wormholes, which is what sends the Traveler to Teyvat. Additionally, both characters share the same Chinese and Japanese voice actors, which seems like too many similarities just to be a coincidence, but it has yet to be confirmed.
Additionally, some believe Honkai's Wendy and Genshin's Venti to be related as well. Venti is the Anemo Archon Barbatos, which is revealed in Genshin Impact's Prologue chapter. But not only is his design strikingly similar to Wendy's but they are both essentially wind gods in their respective universes. It's possible that the similarities in their names could be due to translations, some fans speculate. Their relation, as well as Herrscher's, could be due to a bubble universe created by the Imaginary Tree, which connects the worlds between other miHoYo games as well.
Because of the connections between the two universes, fans are interested to see how they might cross paths in future chapters. The most rudimentary want to imagine the two games crossing over is by Honkai characters appearing in Genshin's gacha. But more than likely, the two stories are somehow intertwined beyond that.
The events currently going on in Genshin Impact could be 500 years after the events of Honkai, meaning that the Traveler was possibly fleeing the chaos before being sent into the future. Other fans believe Genshin might be a prequel to Honkai.
Genshin Impact is available now on Mobile, PC, and PS4, and is in development for Switch. The native PS5 version releases April 28.