Est

The youngest White Wing finally gets a Prf and a refine (actually they all have a weapon and a refine), a rather strong refine. With her weapon granting the powerful ‘Brave’ effect and some extra stats is very deadly to face. There’s a catch though, the brave effect only activates if that are 2 or more flying allies in 2 spaces of Est, which applies pressure upon the players positioning and could lead to foes killing your units if you don’t take care. Her refine basically says, put her in a flier team for the brave effect to work.

Her build is very expensive. Which includes killing an Owain, WF!Hinoka, Brave Celica and Exalted Chrom/Walhart. Blue Flame is probably her best Special in this build, as the build completely relies on allied fliers being adjacent or in two spaces to Est. If you don’t like to invest too much into her or you simply don’t want to kill Owain for this, you can go with Draconic Aura or Dragon Fang. Luna can be an option with a Spd boon and invest into Spd with Life and Death/Swift Sparrow and Desperation, this can be used as a quad build.

Since her speed is too low to quad (base Spd at 30), I decided to go for a OHKO type of build which includes Death Blow 4. Death Blow 3 can be more of a budget friendly option, but you really need all the Attack you can get in order to successfully kill the foe and take no damage. Sturdy Blow can even be an option here if you want to reduce damage taken. Bond skills are definitely one of the other best options here, Flier Formation/Guidence has synergy with Bond Skills and Blue Flame. Atk/Spd, Atk/Def or Atk/Res bond are great options.

Chill Def is arguably one of the best skill options for an OHKO build. Desperation is another option for a different build, its better for a quad build. Investment is key in this build and I think skills like Chill Def may be expensive in terms of wasting 20k feathers to promote Walhart to then fodder him for his skill seems like a waste. Options like Hit and Run/Draw Back are other great budget skills, but this can disrupt the formation of the team.

Flier Guidence/Formation is simply there to bring fliers together this has synergy with Blue Flame and Bond Skills (If you are using them).

There is no dedicated Blue anti-dragon unit in the game. The closest you can get is Festival Ryoma with Cloud Maiougi, which requires two limited availability units. As a result, I decided to try to make a Blue anti-Dragon unit.

Budget or not, Est has the best combination of Attack, Res and Speed. Though her Speed is a bit on the lower side, it's easily remedied by a boon, QR and/or Speed refines to get out of doubling range. She may lack effective damage, but she has the potential to be a solid tank, even potentially a duelist if enough Speed is invested in her as well.

If Berkut is not available, Killer/Slaying Lance and Harmonic Lance are nice alternatives. Regarding her A-passive, I generally try to avoid using Fury on tanks, but it's still not a bad choice both offensively and defensively. For her C-passive, I only used Atk Tactic because it synergizes well with the team she is in, but it is a very flexible skill slot.

Forget the rest, use this Est. The Est archetype is so powerful, it even allows her to use legendary weapons, so she beat up Ephraim and took his lance. This gives her the attack, but more importantly the speed to double some high speed top tiers, such as Odin and Azama. Draw Back gives plenty of versatility, and works great with armors, as well as dragging your enemies into pits. Pavise is here for obvious reasons, this enhances Est's survivability by at least 3 times. Kestral Stance is more of a budget option, however, as Steady Breath is a much better option in actuality. Def Feint is used so she can do lots of damage when her less useful allies rally her. Finally, Odd Res Wave may look like a cheap option, but this skill really allows Est to tank some more hits, and she'll be ready whenever they release magical arrows. With this set, no seal is advised, as to avoid excessive damage loading by your phone leading to a game crash. At the end of the day, this is, by far, one of the best units available in the game.

Alternate offensive build for Est.
With a +Res refine she reaches 36, which means she can speed-ploy almost anyone, and with 5 more effective speed she can reach the same attack spread of Cordelia (35 neutral and 38 if +speed), and like her she can use Heavy Blade seal to activate Galeforce every turn, or use def ploy and Iceberg to further increase her damge output (with her good attack she can 1rko a lot of enemies)

If compared to her standard brave lance set, this has more attack power but also helps with her survability, as she can take some damges in enemy phase without getting killed

Weapon: Berkut's Lance (Res)
Assist: Reposition
Special: Aether/Iceberg
A: Distant Counter
B: Quick Riposte 3
C: Def Ploy / Atk Ploy
Seal: Atk Ploy / Def Ploy
IVs: +Res -Spe (+Atk -Def can be useful too)

Explanation: Anti-mage baiter and debuffer with ploys.

Pros:
1. Mage bait (specially with Red and Blue ones)
2. Great resistance (she can reach more than 40)
3. Good Attack
4. Can recover heal with Aether

Cons:
1. Having problems with Axes and sometimes with green mages.
2. Can't survive to any archer.
3. Need a really high investment to be useful.