I already have Kael and Ignatius at 6 stars.

My next options are Roshcard the Tower, Skullcrusher, Juliana, Coldheart, Apothecary, or Zelotah. I have Jizoh as well, but i think skullcrusher does better in every scenario.

Roshcard is a god in the Arena, but that is really my only use for him.
Juliana and coldheart are both great for CB, good in some dungeons as well.
Everyone rates Apothecary highly, but i haven't found great use for him so far. I've gotten Roshcard's speed so high that he shields everyone before the match really starts, allowing me to go 2 rounds without getting touched.
Skullcrusher is pretty useful everywhere.

I think that down the road, Skullcrusher and Roshcard would be an incredible combo in the arena.

Please let me know if you need any more detailed info.

Thanks in advance!