Absolutely Uriel over Ares. No question about it.
However, if you have Managarm with Tish, then Michael would be a way better choice overall, IMO.You either go Tish and be in a really good spot for the upcoming "just throw Light at it" meta, or since you have Belial, either Svarog (damage per turn extremely high) or Uriel (easily bursts for 2m, allowing you to skip phases in fights).
Up to you, really. Pick whatever you think is the best fit for your playstyle.Well, the only reason not to is your wallet. You could really use a Uriel for Fire or Cthulhu/Vohu for Water.Nothing really stands out to me here. You have plenty of good foundations for teams so you can basically go anywhere you like. That's pretty rare, as usually RNG gives people trash there and gold here, making MTs a fairly simple choice. Your Dark team is clearly in the best spot, but probably in such a good spot that you don't even need to MT for it.
So the question is... what element do you like playing the best?