How do I build my Sophia?

that good IV to against bow users. just say:
weapon: Raven tome
Support: flexible
A: TA 3
B: QR3 or Bow breaker
C: Flexible

Run Triangle Adept 3 with Raven tome, her B slot skill should be Swordbreaker, as red mages aren't relevant enough to run red tomebreaker, and all greens and colorless will do absolutely nothing to her. Quick Riposte 3 is a fine choice to outright kill any ranged units but leaves her vulnerable to swords.

Same IVs as you. She's must more beastly than I expected.