You can restart a battle as many times as you want. When you see your party is dying, pause the game and restart the battle. Try working on different team positioning, disable auto skills if on and see what order of skills makes sense. For example: you dont need ennaras and tus ultimate at the same time, when both more or less do similar things. Start of with Tus and maybe send ennaras next, since tus pushes them back together. xx from Berlin
They each have strengths :/ It feels to me that Flix might be better early game, and Aquiris may be better late game. I do have a video comparing them, so you might check that out and see which one will benefit your team more 😊👍