Roughly speaking, which is better?

Theo628

And who should be ranked up first? Since the prestige is roughly alike.

Fhfjghhggggjfhfjg

Depends on the champs really. Obviously a 4/40 blade will be better than 2/35 groot

Abolitionist333_

The 5*. They get an extra attack of the same champ 4 and 5 wise

Championcritic

5* 2/35

Comparing stats, 5* 2/25 is only marginally better, by like 200ish stats points

Saket_123

5* 2/35

If you have a champ on both then you can compare yourself. The percentage changes for buff and debuff, attack rating, health and debuff and buff ratings are always greater for a 5s than a 4s.