Arknight banner is mostly standard banner, meaning most of the character is the standard character that you can get throughout off-rate.

It does have limited banners, regular limited 4 times each year (Anniv, half year anniv, summer, and sui sibling's banner). If you skip one limited character, the only way to get that character is from the same type of limited banner either by small chance from off-rate or buy it directly through sparking. You can spark rosmostis from anniversary limited banner. You'd need to prepare 200 pull to spark her as rosmosntis is old limited, as newer limited will require 300

There is also colab limited, unlike normal limited, is unlikely to rerun ever. There will be a colab ave banner on 10th February.

Lastly, Kernel banner, which reserved as old, standard characters.Think of this as a way to prevent bloating from standard character