Depends how often you’re going to use her. She has QR3, which is a pretty expensive skill, so if you need it on someone then it’s an option. If you’re going to use her regularly then merge
If she will be on a main team you plan to use competitively (arena offense/defense or first team AA) then definitely merge. If not, QR3 fodder without any feathers spent is invaluable.
+ATK makes her along the same lines as Julia. Boost her up to where she oneshots dragons and her speed wouldn’t matter. She can already tank and kill Reinhardt and is a blade tome destroyer, so build her to her maximum potential.
Pokemon GO
Fire Emblem Heroes
Fate Grand Order
Dragonball Legends
Dragalia Lost
IV Calc
Heroes