Act 8 exploration help
I just beat Glykhan for first time and now wish to explore act 8. Haven't explored anything after act 4.
Got two 6* R5 gems, Herc is my only champ that's R5 now
Please suggest me which champs I should R5 that would help me the most for exploring act 8. Like I ranked up 7* Storm because she helps against Glykhan.