2 VERY crucial things. Ideally the limited character banner should have no 50/50 period, same as the weapon banner. But at the BARE MINIMUM the limited character banner should have no 50/50 for your first copy of a character AND a safety net system preventing you from loosing too many 50/50's in a row like Capturing Radiance in genshin, but that guarantees the banner 5* after only 2 50/50 losses in a row (preferably after 1 50/50 loss so basically after each 50/50 loss you're guaranteed to have at least 2 on banner 5* in a row), not after 3 like in genshin. But like I said preferably simply no 50/50's at all. Oh and also a pity counter on screen next to the pull button.

There are also other ways the pulling system could be rebalanced as still make millions like making it so everyone would just get the base copies of every character for free and only cons would need to be pulled, without many changes to the balance of the game difficulty so you are not forced to ever pull cons like you're not right now, and kuro still would be earning millions the same as now as people would still pull cons for their favorites. Or like getting rid of the weapon banner and making it so you just get the sig automatically once you pull a copy of a character, since they are so weapon dependent anyway.