There’s a way to get an achievement and avatar profile picture in Honkai: Star Rail if you find out where the seven Silvermane “wanted” posters in the Jarilo-VI Belobog Administrative District are. This isn’t an official sidequest. Rather, you only stumble upon it by investigating the wanted posters of the Trailblazer, Dan Heng, March 7th, and Sampo on the map. Once you find all of them, you get a small number of rewards.
To be honest, finding six out of the seven wanted posters in Honkai: Star Rail is really easy. All you need to do is basically check walls in the Belobog Administrative District, as the ones for Dan Heng, March 7th, and Sampo will be plastered on them. Here’s a gallery showing here those are on walls, with the minimap offering more exact positioning.
The tricky one is the Trailblazer wanted poster, as it isn’t on a wall! It’s on a message board. You’ll find it on the western side of the stairs on the northern half of the map.
Also, to make things even clearer, here is the map showing where I found every Honkai: Star Rail Jarilo-VI Administrative District wanted posted.
Once you find them all, you get a 50 Credits!? achievement (which nets you 5 Stellar Jade), 2 Adventure Logs, 20 Shields, and a Wanted Poster Profile Picture.
Honkai: Star Rail is available for PCs and mobile devices, and PS4 and PS5 versions are in development.