I'd go Kael, Stag, Deliana, in that order. In general, we need to be focusing on making more 60s rather than 50s to maximize our resource usage and overall power of champions that we are building. 

Kael will be our DPS and will be fairly easy to gear/build, as well as booking since he's a rare. 

Stag is a pretty huge early pull. 2 turn AoE defense and attack down on a 3 turn cooldown is really nice. 

I'd throw my hat in with Kael as well.  He will be a key part of your early and mid game, in the form of Arena, CB and Dragon.  The latter will be because of the poisons that he brings.

The second one that I would do though would be Deliana

Why do ppl not level up all there champions I've maxed out all the ones I like n keep from there gear to masteries  n accensoin n skills I've maxed out 3 or rare 1 legendary  I epic  n a uncommon dark elf 

Thanks for the advice. haileybug, the answer in my case is that I didn't really know how to do it effectively until just recently. But now that I'm getting the hang of it, I'll be working on a few level 60s.

Yeah only been playing for a little over 2  months  n now I'm going through n getting all weapons n things to be all 5 n 6 star cause it gets a lot harder

I'd go Magnarr or Stag Knight. But I have a love for Stag, since her was my first 6 star.

Kael or deliana , depending on your gear stash( a good 60 kael is good for 12-X and a good deliane is great for 5/6/7-X)

After that its just insanely faster to farm up food . And both option will take you far in game .. im at around 100 days played and deliana and kael still top picks for most content ..and helping get more 60's at a very decent pace!

Because after a while, resources become a pain, especially books, gear and silver. Mid-Late game, you realize that having maxed champions is not enough, your champs need serious gear. Speed requirements for CB, Accuracy requirements for Arena, Crit rate and Crit Damage on nukers......we're talking thousands of runs just to gear out a few champs.

With good gear, you can run some champs at lvl50, but you can't run a maxed champ with crappy gear. Truth is, there are many maxed champions I don't use because I don't have late-game gear for them. 

Are you f2p? If so, go with Kael, then Stag Knight. 

If you plan on spending money on the game, you might outgrow Kael in time, so Stag Knight may be a better choice. 

I think even if OP is planning on throwing a little coin at the game, Kael + Stag or Deliana is the best progression combo now. 

We will outgrow Kael in time for sure, though. But we want to start blasting through content ASAP and this is our best way to do it. 

Kael. He will be your campain farmer.

When I was playing f2p with Kael on my old account, I ran into trouble dealing with Force champions on my way through Brutal (Hallowed Halls and Valdemar Strait). Stag Knight seems to deal with them much easier since he debuffs their ATK and DEF. 

Can't go wrong with Kael, but he needs to be geared decently to make it through. Worst comes to worst, a lvl50 Stag Knight can also help Kael through those Force affinity areas. 

For anyone interested, I decided on Stag Knight, and this is a big part of it. At my level, there's a Deliana meta in Arenas, and Stag Knight provides an easy solution. For what it's worth, I'm destroying teams with a level 60 Kael, even though he's blue and my level 58 Stag Knight is green.

Regardless, I'm on the way to my second level 60. Thanks for all the help you've all given.