Airic

I would go for Xander as Siegfried has Distant Counter built in and higher Def and Res than Eldig…

Brave Lance+ could be interesting on her set, but would she need Bonfire with that amount of dama…

If you want her to be tanky maybe HP+5 or Triangle Adept 3 for the Falchion users based on your d…

Sorry, sent the message twice, crappy net

Could possibly work, also the -5 attack she inflicts might help against non magical units too

Corrin(F) with HP+, Seal Res and Threaten Attack on top of your Robin(F) Threaten Spd could work…