Damn. I didn’t realize the difference in stats that Soleil and Mia had. Should still work out great regardless, but I do want to offer a bit more advice.
Something I would recommend is to swap your C skill or your SS. I didn’t realize the stat difference as well as I forgot about Time Pulse. Unless you’re going up against a unit with Guard or Swordbreaker(Or on the off chance you don’t double) you’ll always activate Galeforce with either Time Pulse or with Flashing Blade(Assuming you get all four hits off). Switching Flashing Blade to SS2 would mean you’re hitting just a point below my Soleil in Atk while always having 55(Or 59 with the bonus) Spd which is what mine hits only on even turns.
Switching Time Pulse to something like a Wave skill or even an offensive Rouse skill if you had it would work great. A rouse would work best with Flashing Blade as you’d still keep an accelerated special which helps for units that die to only 2 or 3 hits. A Rouse also helps patch up the average Atk(I say average but for a Brave user that’s pretty good) or it can boosts your chances of doubling to extreme levels as 65 Spd is a little ridiculous… It’s a real shame that Rouse Atk/Spd doesn’t exist as it’d be the perfect skill for both Mia and Soleil.
One last thing, I’d swap your B skill to Desperation. Nice and cheap, and you’ll see more use out of it than Null Follow-Up. It’s nice to deny disabled doubles, but not many units run Sword Breaker and when you get below the 75% mark(Very easy to do) it’s incredibly easy to KO many units before they can counter.
Up to you on this one, but I would highly recommend Desperation at least. Looking at it now, Time Pulse and Flashing Blade aren’t that bad together. No unit will be one-shot while a decent chunk of units can be two-shot and with Mia’s high Spd will almost always activate Galeforce even if against an opponent you can’t double.