I think the very next thing to do to improve is to get Ninja to 60. He hits very hard, like a truck, and is useful all over the game. Then, I would get High Khatun at least to 50 and equipped up for your dungeons and arena team.

You have some great champs - Sinesha and Sepulcher Sentinel, too! - but you don't seem to be prioritizing right in your gear. Your only 6* champion shouldn't be super slow like that - because she should be having boots with speed as main stat. And Soulbond's got a nice TM reduction, but yours will always get resisted because she has no accuracy. 

Then again, given the other champions you have, Soulbond won't remain very important for very long, anyway... so yeah, just focus on getting Ninja to 60 and make him your main champion with the best gear. 

1. In general, using the same champs everywhere is probably not a good idea. The different dungeons need different strategies to beat. For example, turnmeter reduce is very helpfull at Fireknight und Spider, while Dragon and Clanboss are immune to this mechanic. 

2. Your Soulbond needs other gear. Turnmeter reduce needs accuracy to work, and her A3 with 100% reduce is one reason to use her. I used Soulbond in my Fireknight team in addition to Armiger to hold the shield down. 

3. You have a lot of champs allready that are worth lvl 60. It's a massive grind to get everybody to that stage. I would do only one champ at once, otherwise you end up with a roster full of lvl 50 champs and no lvl 60. I recommend to lvl up the following champs: Fellhound, Ninja, Sepulcher Sentinel, Frozen Banshee, Sinesha, Black Knight, Fenax.

And yes, I would do Fellhound first. With strong equip, he is one the fastest campaign farmers in the game, he can do 12-3 brutal in 6 seconds. That makes the progress of levelling up all the other champs much faster. In addition to that, he is strong at Fireknight, with his reflect damage skill.

That's really a matter of personal preference and how much time he has to play per day / how it's divided over the day. A super fast campaign farmer is nice to have, happy I have my Queen Eva, but for many players it's not worth going to all the effort of building up an otherwise low-priority champ like Fellhound - or at least, not until you've got a whole bunch of higher priority champs done. And in any case, he won't have gear good enough to get the 6 second farming in the beginning, so we'd be talking more like, what, 12 second runs vs 25 second runs with Ninja, or so? 

Agree, I would pass on fellhound and 60 the champs that are most versatile and provide long term progression. 

I feel the same way about passing on another champ that can farm campaign, as soulbond bowyer can do a fine job. And when you're just starting it is also okay to focus on just a team of 5 that can hit Normal/Hard/Brutal CB and also farm the level 13 dungeons. You also try and stay away from 6 starring two champs that "do the same job" when your resources are limited.

Ninja is useful all over the map, from CB to Dragon to Spider to Doom Tower. High Khatun is useful in nearly everything as well, and provides a great speed aura. They would be my next two to 60.

Thank your for the feedbacks, i will lvl 6 ninja first.