Azura

Preferred IV: +RES / -ATK

Weapon: Wagasa (+Res) 

Assist: Sing

Special: Moonbow / Miracle

Passive A: Fort. Def/Res / Fury / B Duel Infantry

Passive B: Sabotage Spd / Sabotage Atk / Sudden Panic / Wings of Mercy

Passive C: Atk Tactic / Atk Ploy / Infantry Pulse / Any Team-Synergistic Buff or Debuff

Sacred Seal: Fortress Res / HP +5

• This is entirely a support set which guts Azura's Attack for the purposes of severely debuffing her opponents.
• With a Resistance refined Wagasa, Fort. Def/Res in her A slot (though Fortress Res can work in a pinch), Fortress Res in her Seal Slot, Azura hits 46 Resistance for which to utilize Sabotage and Ploy skills. You can further utilize her Seal slot to run an additional Ploy debuff if you are comfortable with her only hitting 41 Resistance.
• Alternatively, you can build off or her HP Superboon instead for a Sudden Panic build. HP + 5 can go in her A and S slots (B Duel is a scoring option which provides the same boosts) to give Azura 55 HP after her refine, which increases even further with a season-appropriate blessing.
• Wagasa offers Azura an additional Chill Attack in her weapon slot and as she is the only lance refresher, being able to have this utility is unique to her.
• Her C Slot is the most flexible of all: she can run a team buff, an enemy debuff, or even something like Infantry Flash, or even Infantry Pulse if using her +HP Build. Basically any skill that allows Azura to help her team's combat without seeing combat herself is a net gain.

Preferred IV: +SPD / -HP

Weapon: Vanguard (+Res) / Barrier Lance (+Def) / Sapphire Lance

Assist: Sing

Special: Iceberg / Moonbow / Ruptured Sky

Passive A: Distant Counter / Fort. Def/Res

Passive B: Null C-Disrupt / Wings of Mercy

Passive C: Joint Hone Spd / Def Smoke

Sacred Seal: Quick Riposte / Distant Def / Flexible

• This Azura functions more as an Enemy Phase tank while singing for your team. Due to lance units having easy access to both Vanguard and Barrier Lance, it's easy to pick and choose which defensive stat of hers that you want to focus on, though in the current meta it's generally best to build both defensive stats, hence the alternate refines.
• Running Distant Counter on Azura can help her to take out ranged threats that may otherwise harm your team. Sapphire Lance can be helpful here, as it allows Azura to survive and counter units like Lilina and Lysithea.
• Null C-Disrupt is a luxury skill that Azura can use to counter units like Brave Veronica when they're in annoying places on Aether Raids offense. Note that you want Quick Riposte for this, as Azura will not naturally double due to her lower Speed.

Preferred IV: +SPD / -HP or -RES

Weapon: Lofty Blossoms (+Spd) / Harmonic Lance (+Spd) / Slaying Lance (+Spd)

Assist: Sing

Special: Moonbow / Iceberg / Luna

Passive A: Swift Sparrow / Fury

Passive B: Desperation / Wings of Mercy / Escape Route

Passive C: Joint Hone Spd / Joint Hone Atk

Sacred Seal: Swift Sparrow / Sturdy Blow

• Azura can reach impressive combat heights in Player Phase by inheriting everyone's offensive lance: Lofty Blossoms.
• With a +Spd boon, A Speed refined Lofty Blossoms, and Swift Sparrow 3 + Swift Sparrow 2 in Seal slot, Azura reaches 54 Speed on initiation, allowing her to double often in order to activate Moonbow
• Her lower defenses means that she's guaranteed to hit the HP threshold for Desperation or Escape Route after she gets hit by an opponent, which can allow her to teleport around the battlefield to Sing for her allies.
• Unfortunately, while this set turns Azura into a Player Phase monster, it also means that in order to utilize her combat capability, she cannot Sing for her allies during her turn.
• Joint Hone is the best C slot for her, as it allows her to still play a slightly supportive role while also buffing herself.
• If you'd rather more flexibility for her to Sing in her Player Phase, then Azura can still equip something like a Harmonic Lance or even Vanguard with Fury to bait enemies in the Enemy Phase while singing for her allies on her turn.