Spider is probably the toughest dungeon. A good way to deal with the first dungeon levels is a combination of turnmeter reducing skills (Armiger and Coldheart) and attacks on all enemies to deal with the Spiderlings. In later dungeon levels that doesn't work as good, the Spiderlings have to much hp here.

Don't step into the trap to make to many lvl 50 champs at the start. Your progress will be much faster if you make your Kael or Ninja lvl 60 and use him as campaign farmer. Both of them should be able to beat 12-3 brutal alone at lvl 60, so you can pair your champ with 3 useless uncommens that get xp and serve as food to upgrade others in the end. One lvl 60 champ can produce a lot of other lvl 60 that way.

So get my core group to 50 (pretty much already there) and then work on 60 for Kael or Ninja got it. 

I wouldn't even bother leveling Kael further. You don't need him anymore. Max Ninja and Annie, they'll carry you through most dungeon content. Max Frozen Banshee - she's excellent for Dragon and CB. Max Coldheart. She's excellent for many dungeons.

In terms of order, I'd probably start with Ninja. His AOE freeze is super powerful, and he should be able to walk through Brutal effortlessly, albeit a tad slower than someone like Bellower. After Ninja I'd probably go with FB.

What Skadi said, @Skadi - focus on your first 6 star champ. Kael will carry you as your strongest champ and best farmer for many months to come most likely, until your at a point where you've accumulated several 6 stars and many epics/legos. Focus on using all of your rare books on Kael and maxing out all his skills. He will be a monster once you fully max him, it was a game changer for me. Your second best hero is probably Ninja, atleast for clan boss. His Ascension lv. 3 Escalate ability does a number on CB. And for CB especially, you want to keep your champs' alive aslong as possible. For me, I use 2-3 Attack based heros with lifesteal gear, (remember, the % of healing from lifesteal is proportional to the amount of damage you deal, in other words, you want lifesteal on your strongest ATK based heros.) a support hero with healing abilities/ ally protection, and for the 5th spot usually a void hero that is DEF based. What people call your "Tank". If you want to deal damage and stay alive in CB and Dungeons like Spider and Fire Knight, put lifesteal on a maxxed out Kael, with another gear set like Cruel or Offense, and always have one or two heros on the team that hit the enemy with debuffs like decrease defense, so your nukers can step in and deal even more damage. DEF or HP based heros that can stay alive for a long time and aren't built around Attack are your best bet when it comes to debuffers and healers.

@Spangmastsflex

Have Kael fully booked already, and working on second level mastery scrolls so i guess its time for leveling to 60

Great plan Bob! Kael is an amazing champ and will carry you right through the endgame. He's excellent in CB, as a campaign farmer and is super strong in Dragon. Getting him to 60 will progress your campaign farming and gear farming almost instantly. 

After that, as far as spider goes, Ninja and Armiger will be very strong there, as well as Reliquary Tender. She's an amazing cleanser of the poisons and can get back any champs who fall. You could build her with high def and HP, possibly even in lifesteal or immortal gear, so she will last and keep the rest of the team going as you push farther and farther with a 6 star Kael.

Dont work on Kaels masteries, But them with gems. as long as you cant do Mino 15, farming mino is a waste of eenrgy.

I sstarted with Elhaine had her and Ninja fully mastered and gem mine at level 3 and have after 35 days more than 1200 gems in the bank.

ssecond account Kael fully mastered and gem mine level 3 with 250 gems in th bank at day 13.

Save all your gems and don't buy anything except masteries with your gems.

Booking a legendary is a lot harder than booking a rare, thats why i personally would still use kael.

Unbooked Ninja is still better than fully booked Kael in almost all situations.

 So is it always better to buy masteries?

1. Until you can do mino15 you should buy masteries.

2. Once you can do mino15, if you have an auto-clicker or the Raid Pass you should farm them.

I am late game now, and should do #2 to get XP/Silver and masteries for less gems but it is way too time consuming.  

Only buy masteries for 6star champs.

 Th anks for that been spending tons of exp on masteries

If you already are part way with some champs, probably better to finish in Mino.  Unless u just started, would have to do math to be precise in recommendation... :)

Helps also to have a farmer who can solo Mino 15, because then you can level your champs through that as well as getting their masteries.

 Im working on green scrolls finish first two 

Is shieldguard a good choice for soloing