Help me decide who to promote

Right now I have 70k feathers, enough to promote 3 heroes or promote one for its 5* weapon/skill to inherit. However, I can't decide so I'm asking for your help. Which ones are better to give them priority? I don't need them desperately, so there's no hurry for me if I don't promote the others. Thanks!

Chrom: +Atk -Res
Planning a Brave Build. Need to promote Cain for a Brave Sword+.

Xander: Neutral
Already got our boy, Roy in a horse but DC looks tempting.

A!Tiki: +Def -Res
Planning Quick Riposte/Ignis build. Also, I don't have a 5* dragon in my roster yet.

Effie: Neutral
Should I wait for +Atk or neutral is fine? Planning a Brave build, Abel is there for it.

Cordelia: +Spd -Def
I got her a few days ago, she's my first one so I don't have a build for her yet but I think Quad Lance should be fine, right? Or Firesweep Lance? Got Roderick for it.

Mae: +Atk -Def
Planning a Blarblade nuke build. Need to promote Odin for Blarblade+.

Reinhardt: +Atk -Res
I already have Olwen with the same IV's and everything is working fine to me, is -Res a good bane?

Legion: Neutral
A green unit is always welcome to my roster, "uwee hee hee!"

Fae: +Atk -HP
Planning a Lightning Breath build. Might need to promote Nowi/A!Tiki for it and as I said, I don't have a 5* dragon yet.

Soren: +Atk -Def
I already have a Gronnblade build for him but I'm not sure if that's his best build.

Kagero: +Spd -Def
Planning a Desperation build. My B!Lucina is perfect for her.

Felicia: +Spd -Def
A mage-killer. Iceberg/Glacies works wonder for her and B!Lucina helps her a lot too.

Lukas: +Atk -Spd
Brave build too. Need to promote Abel for it.