Lianna barely feels worse than Lyn at this, if at all. Her stats are a lie, she's really good.
I still don't like Lissa, but I have to admit she's pretty good. I still have her at 60something and she melts manaketes faster than a good number of 99 characters do. Her combo attacks are all pretty committal though, so I'm not entirely sure how to properly fight a certain enemy with her. Strangely, holding guard during C1 cancels it before the buff activates.
Hinoka and Caeda are actually stronger than Camilla, thanks to Luna and Camilla's garbage Luck. Caeda > Hinoka > Camilla against most things, but Hinoka/Camilla having unique weapons lets them clown the dragons and horses in that specific stage. That said, all three feel great to play, but the pegasus riders moreso. Camilla's kind of committal like Lissa, but unlike Lissa she has that nice C5 where the main damage and meter gain is frontloaded and you can just pair up switch right after the axe toss, instead of needing to wait for Lissa C4/C5/C6 to play out fully.
I...really don't like Marth/Celica the more I play them. Their meter gain is low, so they can't use pair up attack often, and it's infuriating when C5 whiffs. Can't use C4 unless you intentionally whiff the early hits, which is risky. Damage feels comparatively lowish too, but I've been playing Celica so maybe Marth's better stats patch that. Unrelated to the arena stage, I had some occurrances in other stages that have me feeling their C6 has blind spots.
Corrin has sorta similar issues to Marth/Celica, but I really appreciate her C4 in arena stages, and her invincible C6 also goes a long way there. I'd dare say I like playing her more than them in general at this point, though I still really like Celica C1.
I actually haven't been playing Ryouma lately, and forgot how nice his dumb C4 is.
Sakura just feels like a slightly worse Takumi, until you have to fight mages. Like Lissa, she shreds manaketes; strange that enemy ones have nothing for Res when Tiki's great with both defensive stats.
Robin's not great for arena maps, but she hits like a freight train and can safely and easily charge pair up attacks with C6. No on-demand stun can be annoying, though, and the hits that actually matter against stun gauges are all at the end of her long combo attacks.
Elise is...way better than I was expecting. I dunno if I accidentally had Luna off her last time I was using her or what, but her damage is totes fine. High meter gain, but more importantly no matter what you can alternate pair up attack > C1 > pair up attack > * endlessly. On demand gold stuns on anything are super nice, too.
I was going to play Frederick, but...