Best rank up option?

Mvrcus

Currently on 6.2.3 story quest, which champs are the best option for R2 or would be most beneficial for the upcoming content (finishing act 6) excluded are my top champs

Crusaderjr

6* spidergwen is great for annoying evade champs and if you are skilled you can power control fairly easily.
6* iceman for the immunities
5* hulkbuster, kingpin, bwcv, human torch. (plenty of other options like corve and rogue) but the others have multiple attributes that will make it 100x easier in overall situations.