Unanimous Duchess votes. Figured as much.
I do lean to Duchess simply for Hydra. If I replace Pythion with Duchess on my Hard team, I gain consistent Veil & Inc Atk, and everyone on that team does damage based on Atk, so I could see a significant jump in total damage there. It could realistically push me over 400M (800M Clash) for that team. Elva simply cannot match her in that spot.
Duchess has been my most-wanted toon for a very long time; however, I have actually come to the conclusion that my account will never have a Duchess. I pull shards every time Duchess is boosted, but she never finds her way home to me. I have pulled more shards for Duchess than any other toon.
Not sure how much Classic and 3v3 usage either of them would see. I am pretty good on support in Arena with 2X Pythion, 2X Ukko, 2X Kymar, Arbiter, Siphi & Mithrala all built out and tuned into teams.
For Live Arena, Duchess wins hands-down.
For general all-around utility, I actually gravitate to wanting Elva just because she has a Cleanse & Inc Speed with her Block Buffs...which I find more attractive than Inc Atk & Perfect Veil.