I love few things more than making up my own conspiracies about Honkai Star Rail, Zenless Zone Zero, and even Genshin Impact. While the third of Hoyoverse's smash-hit games isn't involved here (yet), you never quite know. Here's my latest theory about a worldly crossover between the two titles.
In the latest Honkai Star Rail update stream, during the trailer for 4.1, we see some strangely familiar shapes. If you're a ZZZ player like I am, your mind may have gone to the same place: "Hey, aren't those the Starlight Knights?!"
In Zenless, they're the stars of an in-universe TV show that you learn about very soon, thanks to ZZZ's Billy's obsession with them, and him being a starting character you get for free. There are four Knights - a red, a green, a yellow, and a vaguely blue or grey one. You sometimes see them on the game's TV loading screen, and the video store has at least one tape featuring them that you can rent.
While there's no actual confirmation that these heroes would become playable (yet), there are some hints that lead me to hope we'll get a team of them. For a start, where the heck is our S-Rank version of Billy? Anby got one, and Nicole got a fancy skin, so what does our boy get? He already vaguely looks like the red Knight, so it's an easy design to make. In April 2025, the Zenless YouTube channel posted an EP featuring the Knights, too - why would they do that if there was nothing coming of it?
Back to Honkai Star Rail - during the 4.2 trailer, and explanation of the upcoming in-game events, we see four figures dressed in red, yellow, blue, and white, with gold stars on their chests and helmets. Who also has gold stars? The Starlight Knights. In the same places on their uniforms. Coincidence, I don't think so. They do then turn into mechs, but what is a mech if not a robot? Who else is a robot? That's right, Billy.
In conclusion, wouldn't it be fun if we did actually get an S-rank (or five-star) Billy, but he was in Honkai Star Rail, lost across the universe from New Eridu? We already have physical-using, gun-toting characters (Boothill, my main), but maybe Billy could use a different element and keep his quintessential pistols.
Anyway, this is all just a game theory, and they're probably just oddly similar characters based on classic tropes like Kamen Rider and the Power Rangers. Tune in next time to see what cross-universe cracked theory I cook up next.