Without seeing your roster, the only answer is "maybe".

where are you trying to improve at the moment? you've got a number of champions that are worth taking to 60, but not every champion will be helpful in every area. for example, coldheart will be of great use when it comes to the fire knight and spider dungeons (as well as a few doom tower bosses), but will be of limited use elsewhere.

additionally, stop spreading your resources across so many champions. you'll have a much easier time progressing if you just focus on bringing champions to 60 rather than making a bunch of level 40 and 50 champions. until you have plans to bring a champ to 60 (or you're levelling it to use as food), leave it at level 1.

Well, you've got no shortage of champs definitely worth taking to 60.

I personally recommend an approach of working on 1 champ at a time; scrolls, books 60, gear, then start over on the next champ, rather than splitting time and resources between developing multiple champs at the same time.

The question is: which area of the game do you want to/need to improve next?

Coldheart is excellent in quite a few places. I have 2 fully maxed.

Hepharaak is an arena monster, as is Warlord

I love Rhazin, but you have other champs to prioritize ahead of him who will be more useful overall

Well right now Im working on fire knight so besides coldheart who else do I need to focus on?

Rhazin is good for FK

Blizaar is okay for regular FK, and he's good for waves cc. Eventually you'll almost certainly want him for Hard FK

How far are you from Visix? double hit a1 with tm redux is pretty good.

Im less than 120 in....so no where close to Visix yet....

Id look at taking Stag up as well.  Get you AOE defense drop for the waves and a decrease speed for the boss.

Ninja is apparently really good all around. Surprisingly I've found Oella to be very impressive, especially on Iron Twins and Demon Lord. The other issue is Books. Coldheart is the easiest to fully book. Stag Knight is also a great choice because of his Decrease Def + Dec Atk AOE, extremely useful early on for clearing Round 1 and 2 of Dungeons.

I will tell you this, you've got about 10+ Champs that you should 60 before Rhazin so just ignore him outside of Faction Wars for now.

Oh and side note, please fully ascend Krok'Mar ASAP. He is really useful and deserves the potions.

Final Verdict from me is purely going to depend on if you have legendary tomes AND if you currently have Fire Knight stage 20 on 100% Auto Farm. Coldheart+Apothecary will make FK20 very easy.

Ninja is great for Clan Boss also, and getting Nightmare and Ultra Nightmare chests daily is going to boost your account the most. 

Don't worry about Arena too much. You have Wukong and you can get Gold V just by killing the 1 Man Teams as long as you're refreshing the list often enough.

Your FK 20 Team should be: Krok'Mar, Stag Knight, Apothecary, Coldheart and Vogoth (based on your current roster). You probably can't get everyone to 100% Crit Rate with early gear, so Krok helps there. Stag makes waves easier to kill, Vogoth does AOE CC with Provoke and heals against boss (Plus 3 hits on A1).

First thank you for these insights! This really does help me focus what I need to do to get what I want done! Ninja, Krok, Apothecary, coldheart, and Vogoth are all on my list to make 60. But you said 10 and Im curous as to which 10?

Stag, UDK, coldheart, vogoth, hepharaak, warlord, ninja, apoth, uugo, serris

Bellower is exceptionally good in a stun set as cc for waves, especially with the new blessing that turns small debuffs into big ones

tayrel is also a consideration.

Blizaar will probably be vital for Hard FK, but you probably won;t be there for some time.

Yep I actually had Bellower in the spot of Serris for the 10 I was gonna say. Honestly, I think I only fused Rhazin for the Mission. 

Rhazin.... god I feel so bad for him. He was a one-trick pony really, his AOE 100% Turn Meter depletion was godlike but otherwise he didn't stand out much... now with Armanz he's completely obsolete it seems.

I mean lets look at it. Rhazin's A3 doesn't even steal TM, it just reduces it... and it's BOOKED at a god damn SIX TURN CD! Armanz is 100% STEAL and is on a 3 turn. I hope he gets reworked soon. Poor poor Rhazin...