Unlucky .... 

Wow you have Fayne. REALLY nice dps/debuffer for CB, I'd highly recommend developing her if you're wanting a CB team. She also fits into unkillable double maneater team that i run in the future, she's the last piece im missing haha. Seeker is also part of the unkillable team and a great epic overall to develope.  You could also consider Tayrel for overall content, great aoe dec def and single target dec attack for bosses. You seem to be at a spot where you need to get your hands on some beginner sets. 

Dragon 20 would be your goal as you can farm speed/toxic gear for you clanboss team and overall content.

In my opinion I'd say you're at a great start with that roster and would focus on the champs i mentioned. my personal first choice would be Fayne just because she's a phenomenal clan boss dps and can be a good boss killer for dungeons.  You have deacon so you can develope Tayrel later maybe. Then you can progress your new maneater for his aoe dec attack on a1. That takes care of boss dps, debuffers, wave controller. 3/5 , now you can fill in Kael for overall wave nukage as well as boss dps since he's leveled already 4/5. Now I'd say run a support you like, I'd say Apothecary since he's already build nicely for you and you can use Maneater buff to help clutch out some moments 5/5. 

That'd be a solid overall team to use until you get more gear and units up to start building specialized teams. You could even swap Deacon out for Tayrel later as a beginner clan boss team. Once you get going a bit and can move maneater/fayne alongside seeker into more special clan boss teams I'd consider developing coldheart to fill in the boss killer dps role, and by then you hopefully have some better gear to move around and might even pull a nice aoe dec attack champ to fill in maneater's void as well. Overall you have an awsome start with lots of content for you to work on for now haha. Hope this helps a bit, Goodluck!

Pro Tip: This game is all about resource management. Really be picky with where you spend things, and keep an eye on upcoming events/tournaments for stuff before you waste all your resources. Things like free gear removal events are more midgame/lategame but can save you millions in building out champs. Try not to refine too much until we have gear refinement events for free rewards for your silver spent. I'd say you can save those chickens you have for the next champion training or clan v clan event so you'll get free energy and stuff for it. For now you can really focus on farming up more chickens( you never have enough chickens) unless you're at a point where really taking someone to 60 will open up the game for you more.

You are a Star @Plz RNG , Thank you so much