Atk/Spd Bond for F!Celica?

A more enemy-phase oriented build would be better imho. Somthing like brazen atk/def (or maybe atk/spd?) + qr seal and a 3 turn special or aether. The idea is that she would have a strong first encounter thanks to her weapon, which would be then followed by activation of brazen which would make her even tankier (in case of def brazen) or speedier (in case of spd brazen) so that she can participate in more battles without being too reliant on positioning based support.

I'm not a big fan of bond skills. The bonus is great, but the requirement is a bit much for me to take for general purposes, because the positioning required is a huge drawback, since it often means that you have to waste a unit's turn (or force it into a disadvantageous position) just to place it next to your bond user. I find it only valuable if you have warping skills (WoM, Escape route, flyer stuff), a pure bait unit (a DC tank) or a synergistic unit (owl tome)

Bond skills aren’t that good- let’s be honest. Sometimes it’s hard to place your unit adjacent to another without them being in enemy range.
Fallen celica doesn’t really have to worry about speed since she has chill speed (super good skill btw), BUT! I’d absolutely recommend swift sparrow if have a SM Eirika or something lying around since it doesn’t reduce defense like life and death does.
I do wonder what IV your precious Celica was for you to let the -spd variant live though.