Rank up advice: 5*duped Colossus or 6*unduped Colossus

iRanjan

I run with a 5*duped fully maxed Omega red, a 5*duped fully maxed Magneto and a 6*unduped Emma Frost most of the time. So I'm hoping Colossus will be a nice fit here

However I'm very confused whom to rank up (considering how difficult it is to dupe a 6 star champ). The armour ups on the 5* Colossus scale up well through the fight but the 6* Colossus has more base attack and health. So confused, any advice will be appreciated.

Thanks in advance for your time and help