Teambuilding Help

I'm having some trouble building a good defensive team, although I wouldn't mind some thoughts on offensive teams either. But I need some thoughts on team options. In the long run, I want my team to be Nowi, Soleil, and then either Fae or Nino. Right now, my main core is Nowi, Myrrh, and Alm, often paired with Fallen Takumi. Note that none of these are merged except for Masked Marth, who's +1.

List of my strongest 5-star units:
+Def -Res Steady Breath Nowi (Lightning Breath)
+Spd -Res Windsweep Alm (Falchion)
Neutral Healer Masked Marth (Falchion)
Neutral Earth Boost Renewal Marisa (Wo Dao+)
Neutral Vanilla VL Ike (Ragnell)
+Atk -Res Vanilla Zelgius (Alondite)
Neutral TA Lyon (Naglfar)
Neutral Vanilla Fjorm (Leiptr)
Neutral Fortress Defense Brave Lucina (Geirskogul)
-Atk +Res Vanilla Micaiah (Thani)
Neutral Fury/Desperation Anna (Noatun)
+Res -Hp Vanilla Dorcas (Stout Tomahawk)
Neutral Flying Nuke Cherche (Brave Axe)
+Res -Spd TA New Years Azura (Hagoita+)
+Res -Def QR 2 Myrrh (Great Flame)
Neutral Bowbreaker NY Corrin (M) (Hama Ya+)
Neutral Fury/Desperation Fallen Takumi (Skadi)
+Res -Def Green Death Blow NY Takumi (Kagami Mochi+)

Not built:
+Hp -Res Siegbert (Dark Greatsword)
+Res -Atk Green Tomebreaker LA Roy (Gratia+)
Neutral Vanilla LA Eliwood (Casa Blanca)
+Def -Hp Hinoka (Hinoka's Spear / Brave Lance+)
+Hp -Atk Tiki (Y) (Flametongue+)
Neutral Black Knight (Brave Sword / Alondite)
Soren (Forgot IVs)
Ryoma (Unusable IVs)
Tailtiu (Questionable IVs)
Ike VL (The free one)

I have 23k feathers and was thinking of building Fae next.