High Khatun: You mainly need her for her speed manipulation, so getting her to 6* will not help much with that. I see many at 4* and 5* in arena as the lead.

Warmaiden: Her main function is her A3 60% Dec. Def, again 6* wont help with that skill, but I do see more WM at 6* in arena, as she does have better attack than HK

Spirithost: Same as above two, main function is atk buff for alies, and debuff removal and block debuff for all allies. She is support so not much attack from her.

Roshcard the Tower: Looking at his skills he will be helpful to your team as support with all his buff/debuff skills and HP aura. Being a Legendary getting him to 6* should be helpful  

Juliana: Her A3 HP Burn would be great in clan boss, I have a Bulwark and he is great as my lead in CB

Bellower: I would say Bellower should definitely get to 6*. He is a support champ, but with his 3- AOE skills can be geared for lots of damage.

FYI: I only have the first 3, so info on the last 3 are from different videos, this forum, and learning more about this game over the last 2 months (COVID work from home)

Good Luck

I gotta ask first- have you gotten you starter champ to 6*

If so, I think either High Khatun or Warmaiden will do. 

You seem to be early stages of the game so i say Bellower he is an void, all atacks aoe and has debuffs.. he does not have weak stages so you'll use him in every stages. Also later in the game when you have more and better champs you can still use bellower with stun set for controll

Artalz said:

High Khatun , Warmaiden , Spirithost , Roshcard the Tower , Juliana , Bellower

 I wonder - these six are the only champions you have or these are the ones you think are worth the effort? 

Daering said:

Artalz said:

High Khatun , Warmaiden , Spirithost , Roshcard the Tower , Juliana , Bellower

 I wonder - these six are the only champions you have or these are the ones you think are worth the effort? 

No, I have other champions, but these are the ones I have 5-starred and currently use the most.

I wanted to upgrade Bellower but I didn't have the best Stun gear which I wanted to put on him, so I ended up upgrading Roshcard.

Thanks everyone for your suggestions!