FIrst, you need a team of Jizoh, Gnarlhorn, Harrier and 2 more useless 5* (although Gnarlhorn isn't completely useless) to get a campaign farmer to rank 6. 

Your first order of priority should be maxing a campaign farmer, stop 5-staring every shiny new toy. 

Agree with this.  I would probably take Kael to 60, even though you have Trunda, largely because Kael will be much more useful in other content (such as Clan Boss and Dragon) than Trunda will for your account at this stage.

Once you get Kael to 6 star, you should be set for a bit.  Also, don't worry too much about Nightmare campaign right now once you get to it.  Instead, focus on pushing ahead with CB a bit

I disagree with Balltazer's recommendation. Do NOT use Gnarlhorn as food in tavern. He is one of the champs needed to fuse the legendary Rhazin Sacrhide.

Be very carefull before you use any champ as food in general, you should only sacrifice champs where you are sure you don't need them. And be especially carefull before you use champs as food that have the fusion symbol in their avatar.

i

 I made this mistake of feeding champs from the Rhazion fusion. It took me nearly a year until I got that particular rare I had sacrificed again. 

gnarlhorn is already at rank 5 though, which i'm pretty sure means he can't be used to fuse rhazin. if so, he's fine to use as food. i also disagree with balltazer, but in my case it's their recommendation to use jizoh. i wouldn't advocate using any epic champions as food unless you already have a copy of them.

You can use overranked champs to fuse, have made that mistake before. :)

Agree with keeping all epics and fusion rares that aren't farmable.

Would take Kael to 60 and then there's some really good options there for campaign/overall purposes. I want to say Apothecary because of how well he'll do in overall content and ease of booking out, but I can certainly see a case for Trunda and Ronda next, too. 

Great start to the account with Trunda/Geo/Skullcrusher pulls. Keep up on the food grind and you're going to have quite the account going.

Good call, I didn't catch that. My point was that he needs to 6 star a farmer before he goes any further.