Who to pick 6 star? Thronebreaker player here

Amanda_Cruze

Both are new champ.

Already have undup Doom and sorcerer supreme as 6 star unduped

Excelimus2009

That depends on the type of content your doing. I can't say much about Ironheart but Diablo with synergies is kinda awesome. Note: only tested with KP synergy and still learning.