Updated my Castle with the following:
Corrin: Poison Strike, Savage Blow, Demoiselle, Death Blow, Shurikenbreaker
Niles: Lethality, Astra, Luna, Counter, Countermagic
Shigure: Grisly Wound, Even Better, Better Odds, Evenhanded, Odd Shaped
Anna: Counter, Countermagic, Death Blow, Poison Strike, Savage Blow
Hayato: Counter, Countermagic, Gentilhomme, Inspiration, Renewal
Nyx: Counter, Countermagic, Good Fortune, Renewal, Astra
Charlotte: Axefaire, Counter, Poison Strike, Savage Blow, Rend Heaven
and there's a Candace hanging around if anyone wants to recruit her!