3 shiny new banners with a lot of choices.
From what they've shown, Brave Micaiah is the top choice (a FLYING GREEN MAGE), followed by Braveliwood (free anti-beast dude) and Brave Alm (for sheer damage) in a tie, and Brave Camilla being less impressive than Brave Veronica (except Brave Camilla has more 1-turn offensive potential as a healer...plus, she's flying).
II'll need to see her unique B Skill, which is represented by Yune, before I start calling her the top choice.
her neutral statline 36 HP, 51 Attack, 28 speed, 17 defense, 40 Res
is fine, but not exactly thrilling. She's basically min/maxed version of normal Micaiah. Which is totally usable but you're dealing with a character that's only ever going to hit once unless the B Skill is super duper QR or else you gotta put QR on her in general.
Honestly Eliwood stands out to me the most in sheer versatility. His double effectiveness weapon is great, especially for the beast effectiveness which is still really rare. His +4 to all stats effect on initation is great if only for its consistency. His movement type is great and might pair well with galeforce though he might kill things a bit too easily.
Statline is abotu perfect for what you want him to do mostly
40 HP, 53 attack, 38 Speed, 32 defense, 18 res
The low res might be in his favor for setting up other strats by taking a hit from dragons but we'll see how that works in practice.