Perfect Sophia

Well... Sophia's stats are better for the role but her color is worse. It can still be worth it, especially as a specific counter in Arena Assault, but it really depends on the team comp that you're running her in. Counters are great for keeping a specific threat - like Brave Lyn or Reinhardt - from decimating team members who are weak to them but the game is designed in such a way that they're not broadly useful (i.e. they will have more unfavorable than favorable match-ups...but ideally in said favorable match-ups they will always win).

That said, I probably wouldn't promote her to 5*. She's an easy one to merge to 4* +10.

Like I always said, she's a mediocre unit at best. She has an extremely niche role she can fill decently enough, but not even that great at it(her color hurt her a lot indeed). She cost tons to build and she cannot run any other set so she's extremely limited. I personnally would not invest into her as a f2p player as she fills a way too much specefic rôle. Sanaki already has TA, a legendary tome and a great atk to use blade tome Robbin already has the tome and so does Cecilia so they are WAY easier and more usable than her(Cecilia can counter both Lyn and Reinhardt!). True sanaki has bad availability, but the other 2 are more available and have better color.

I strongly believe that recommending/building this hero is a mistake, unless you have a lot of ressources to spend. If you have that many roy sitting on your barack, I am very jalous ;)

I built an almost optimal(+atk/-res) Raventome Sophia to 5*, and I have to admit, I did find her slightly underwhelming (but I like her enough, so I don't regret it). Mainly because you have to CHOOSE who you want her to counter - running Bowbreaker to obliterate Lyn and Cordelia means she loses out on ORKOing Hector on initiation, for example, which is a dilemma other Raventome users don't have.

Because of this, I'm planning on rebuilding my +atk/-res Lilina into a Raventome user. But that's not to say Sophia is utterly outclassed in that niche, she's the best Raudrraven+ enemy phase unit, and quite a "safe" unit, factoring in misplays and miscalculations of the AI, which I always like to take into account for arena runs. Sanaki/Lilina are just better at straight up ORKOing all greens and colorless on the player phase, BUT even with Raven+ & TA, they have a shaky matchup against BLyn, at least for my liking. Can't run a calc now, but last I checked, she can beat them if she procs her special and has either a goad or hone effect active. So Sophia definitely has her own niche. I mainly decided to promote her because I want a Raven users of every color for AA, and all my other red mages are relatively frail sweepers (Celica, Tharja, Katarina).

The set I run, S Supported with Fae (Lightning Breath+, TA3, QR3) who absolutely sharts on all blues esp Rein, forming an anti meta pair which easily handle Reinhardt and all blue units, Brave Lyn, Brave Ike, and Hector, freeing the rest of my team slots:

I think you are using them wrong. They are both amazing in AA. My M Robin kill almost everything in Red and Colorless. Sophia is a little bit weaker but as a counter she works really well for me.