Unfortunately that is way too many things to focus on at one time. This game is really built around trying to trap you into spreading your resources too thinly, in order to entice you into buying stuff to make up for the lack of focus.
What you need to do is pick one specific area to improve, and focus on that. Just to be clear - I don't mean "focus on dungeons". I mean even more specifically, "focus on Dragon", for example.
To extend on that thought - objective number one is to get a champ who can solo farm Brutal 12-3. I think you've already done that, likely with Kael.
Since that objective is complete, the next objective needs to be getting Dragon 20 on farm. Going through this thread, I can't find specifically which one you are doing, but I do not think it is 20? If that's the case, you need to build a team that can do that effectively.
Looking over your roster, you have a ton of champs. The ones I'd specifically use for Dragon 20 are:
- Scyl (insurance revive, AOE CC for waves, passive heals)
- Lanakis (strong damage for the boss)
- Roxam (good waveclearing and face damage)
- Cleopterix (good waveclearing and CC)
- Kael (poisons for the boss)