Who do you think is the better unit to recruit on Celica's route, Sonya or Deen?
This is arguably one of the hardest decisions in the game primarily because Deen has been greatly buffed from OG Gaiden and as a result the competition between them is way tougher.
Deen is overall more durable than Kamui, generally faster than Saber, and stronger than Jesse.
Sonya will be faster than Boey but she won’t be as durable as Boey or as strong as Mae but not as frail, however not as versatile as Celica until promo.
The issue with Sonya is you get so many magic units in Celica’s route not to mention Celica herself is a mage, healer, and sword user all in one and Mae as well when she promotes.
Deen also has to compete with at least 3 other Mercs and 4 should you make Atlas a Merc.
Basically you can really pick whoever you want, there is no best choice.
If your mages have been doing poorly maybe get Sonya, if your mercs have been doing poorly maybe get Deen.
Personally I got Sonya, I like her character over Deen’s