There once was a prophet from Nabata. She was slow and deemed useless by many. Everyone knew her, none would consult her. So she waited in isolation, ranked among the lowest of warriors while mages and archers and ninjas were hailed as the greatest heroes of our time.
But she grew strong.
And she learned how to get along!
(Not pictured, Julia, Nino. Results will be the same.)
Archers got you down? Kagero wrecking your team? Green mages make you sad? Why not try Sophia? The slowest mage in the game, and the perfect counter to the current green and bow heavy metagame.
Yes, I did just take the "worst" mage in the game and made her into an anti-meta counter. And she excels at that job. Now you might ask why not Lilina or Henry, even? Lilina can't do this. She would get destroyed by Kagero, TA or not. And Henry, despite getting Raurraven+, does less damage than Sophia. Only Sophia sits in this exact middleground where she both ignores archers and axes AND can hit back hard enough to kill the ranged enemies. After a bit of skill inheritance shenanigans, of course. She needs that Raurraven tome. And Triangle Adept 3. And Quick Reposte, but we just got a free Subaki, so that one is easy to get. We also got a free Palla for Moonbow. Triangle Adept might be harder to get, I had a four star Roy. That'll teach him to troll with a movie for a four star pull.
Getting a perfect run with her on the team was easy. Nothing green or colorless can seriously hurt her. Kagero up there is one of the bad ones. A fully buffed Gronnblade+ user can hurt her, too, but those are rare. And easy to split off when the AI runs her. In most cases, Sophia will just take a hit and destroy Nino (Or Cecilia if that's who you're bladin' with.) Of course, a fair warning needs to be given. While she is functionally immune to all green and colorless foes, she really REALLY should not tangle with anything blue. At all. Reinhardt will wreck her. Linde and Robin, too. Blue melee is bad for her as well. Which is why she's teaming up with Nino. They kill each others' counters.
Oh, and if taking Sophia to five stars might be a bit steep for you, it's okay. She still counters Kagero at four stars with this build. She will lose out in some Red vs. Red fights she'd otherwise win, but four stars and Triangle Adept 2 is actually enough for a stopgap solution to archers and ninjas. I just went further with the idea instead.