Kael is your only level 60 ? 

Id say White dryad Nia and Sun Wukong ( a general support and another dmg dealer , one epic , one leggo , both will be good even in endgame )  

Then id stockpile 5* food/chickens to start a good CB team while posting another thread once you're ready to tackle that part

Yes, Kael is my only 60 at the moment. I took roughly a 2 year hiatus and just started back to playing. Thank you for your advice!

Kael does a good job of doing either waveclearing OR debuffing. Doing both is tricky for an early game player. I'd probably focus on the latter. Build him with speed and accuracy so you can keep poisons on Dragon. So, I'd probably build Bellower next. You'll use him for campaign farming, in a Lifesteal set if necessary, though ideally he'll just clear the waves without needing it. For your dungeon teams, you'll want to build Tayrel and Doompriest. For now I'd run those five for dungeon teams, until you get Scyl, who can take Doompriest's place.