imo
Best Faith: Hera
Cons from Ares: -800 Atk (if skill, it become -2400atk deficit from hera)
Pros from Ares: +1300 crit (13%)
if you equip full might gear (atk & crit) you can get up to 40% crit and only -800 atk from ares, meanwhile ares can only up to 20% crit if full might gear