Usually the repeats are the ones that can consistently generate more revenue. Wouldn't be surprised to see another Bellona banner.

They should do multiple banners per week or even every 2 weeks, it will increase their revenue and people can choose who to pull for. They can release 1 hero each from each element (apart from light and dark obviously) and 1 of those being a new hero. 

An example is in the current banners: Diene (Water), Alencia (Earth/New hero) and instead of Charles they release a fire banner like Cecilia. All will rotate out at the same time persuading people to buy more packs thus increasing revenue while giving players choices. Or since Diene is a limited they should group limited and new heroes together, don't make them overlap like in my example.

Just my thoughts lol  

Ludwig is a pretty solid unit if they gave him ee he'd be much more appealing to use.

They are starting to put up more banners.

recent banner is Diene ( Ice ) > Krau ( Ice ) > Alencia ( Earth ) > Charles ( Earth ).

I hope next is Fire ..Charlotte along with her EE and Buff :)

Thank you for your suggestions on the banner, Heirs! I'll convey this to our team so that they could consider featuring Ludwig (or other heroes) in the future banners. Thank you!

I have Ludwig, had him since game launched. I know he has been buffed, but he still seems like a niche PvP character. I don't find him useful at all. I see he works well with Elena.