Hi, my tip:

In addition to the 4 existing modes, I’d suggest a 5th one: exploring the Praetorium. (Here’s an image showing what it might look like.)
Players would explore the map and fight monsters, with each chapter ending with a boss that must be defeated. This would be limited to, for example, one or at most two elements. You would never have a choice from all elements (or only at the beginning); the further you progress, the harder the difficulty becomes. Along the way, you’d collect resources, cards, other items,sps, etc.
Traveling would consume energy; when it runs out, you’d have to wait a day for it to recharge, or you could buy more somewhere.
This would add another layer of variety, as you wouldn’t just be playing for chest rewards—you’d be progressing through the map and experiencing another story. Rewards could also include unlocking avatar items or a title for completing the entire map.
Another model could be something like selecting a set of cards (e.g., 15–20 plus the summoner’s card), and with this expedition party, you’d have to navigate through certain waves of enemies; alternatively, you’d have all cards available, and defeated cards would be discarded, similar to the Survivor mode.