Flier Team

You have one copy of Azura and she has +Spd/-HP??? (ideal IV) This luck of yours is heretic! To the stake!! BURN!!!!

(Actually, my only Azura is +Spd/-HP too. lol)

Merges are important. I would use Cordelia over Tana. Tana does nuke well and can occasionally tank melee unit. But that is not as useful as the absolute nuking power of Cordelia in my experience.

With Cordelia, your Cherche is bound for retirement. Unless you want to collect another 10 Cherche. 4* +10 is a very temporary patch to any team. Try replacing her with Beruka or Minerva as your resources grow. You already have Elincia. A physical melee tank is more useful.

You do need to keep Camilla as that is your only DC unit.

Now, with Elincia, Azura, and Camilla, your 4th unit has to be a bonus hero. I wouldn't count on one of your fliers to be on the bonus list every week. So in the ideal world, you actually won't use Cordelia or Cherche or Tana. But of course, you need the merges and you may have to give up a low scoring hero when needed even if she makes a better team. (That hero may be Elincia btw.)

All in all, if you are set on using Elincia, I would ditch Tana for now and use Azura's sing to compensate for the lack of melee tank. Tana just doesn't tank hard enough. Between Cherche and Cordelia, use Cherche for now since she gives higher score. If you have an over abundance of feather or if you really like Cordelia, merge Cordelia and replace Cherche. Otherwise, save your feather for a +10 Beruka or something. +10 regular Camilla with DC also works well.

Right now im running a flier team with
H! Nowi +atk - res
S! Camilla +spd -atk (unfortunately)
Elincia +spd -def (+1) and
Cordelia +3 4* +atk - res
This is by far my best team as theres so much synergy in it.
Id personally suggest (if you have the fodder) change S! Camilla into a blade build if you plan on using her. Elincia is good but she cant hit very hard without buffs. In my experience she dies most of the time before she can do some damage. I use her as a finisher if nowi or camilla cant one shot the enemy. Definitely use NY! Azura as that will make attacks from S! Camilla that much better and then Id take Cordelia over Tana since she has better fire power. You can run a firesweep build but if you're trying to clear hard maps like chain challenges with this team then do a brave build for Cordelia instead. The extra speed can help her quad more enemies.
Thats my two cents on it and my experience with my flier team. Ive managed to beat all the chain challenges with that team but of course all teams are different. Good luck mate

You have great units, but for T20 arena are very limited with merges.

My suggestion to you is:

* Elincia
* Cordelia (and merge her the fuck up)
* Azura
* S! Camilla over Cherche. You really NEED at least one range, your Camilla has great IVs and can check B! Lyn and Reinhardt.
If by the time you got your Cordelia to +10 you haven't been able to merge Camilla up (or they didn't release a better green flier), then I'd consider switching to Cherge for merges/score.

You have time, and a very solid base. Start working on that sweet Cordelia (I have the same one and she's amazing) and in a couple months take another look at what you got.

If this is your main arena team I strongly suggest you spend whatever orbs you get until the end of the banner on Azura Merges. It's gonna be a long time until she's back again, and she's definitely a keeper.

If there's no Hector on a Banner before that (I'm in dire need of DC for my armors), I'm gonna do just that for my own Azura.