Lyn

Of course she can, the refinement pretty much guarantees a follow up, so she can double even the speediest as long as they can counter. Best a skill is Fury since it puts her in the Desperation and Brash Assault range, as well as the Wrath range which is her best b slot, but Vantage is also run on her for the cheaper option. Best special is Moonbow when you have Wrath, otherwise go with Luna, Bonfire or Iceberg (since with res bane and Fury, she hits 29 in both def and res, so either one works). Slap Repo and Threaten Def with an atk seal and you're set.

That's like the perfect IVs for her, to help her deny almost every double in the game outside of breakers. Gotta think not just about her on the offense. Inevitably, she's gonna get attacked at some point, so you have to think about her survival as well.

+spd is great on her.

For A skill: I'd go with a Brazen Atk/Spd or Swift Sparrow, or more budget Death Blow. Fury has great synergy to help her get down into her Effect range.

For B: Wrath is amazing and is almost the same HP threshold for her Sol Katti. More budget, a Breaker Skill: swordbreaker helps her dual the other fast swords (Ayra, Mia).

For special: Luna, or Moonbow

For C Skill: anything. I like the Drive Skills, a threaten skill (Defense/Speed), or depending on team composition a tactic skill.

For Assist: Reposition is great on everything, Reciprocal Aid or Ardent Sacrifice will help into her effect range.