Oh… I thought of another one. What do you think of an Infinite Wave Challenge (or something with a much cooler name)? My thought is, you’d have a challenge with no set number of waves. You pick your five heroes and your battle items like normal and then you start off against either regular enemies or bosses. Once you defeat all the enemies/bosses in the first wave, you move on to the next wave. The next wave increases in difficulty, as does each subsequent wave. And the waves keep coming, each increasing in difficulty, until all your heroes are dead. The object is to get as far as you can before dying.
Your loot continues to grow, as well, the deeper you go, the better the loot. This can be a challenge event or a quest or daily tournament, or just a “practice”. No continues allowed and you can have a daily leaderboard.
I got the idea from these current missions and farming where my heroes are all full at the time of completion and I’m like, “I could’ve done this two or three more times”.