Rinwell > Mint:

I'm not a fan of the Tales of Arise combat system.  Basically everything depends on whether you can predict when and where an enemy will attack and can hit the dodge button at the perfect moment to avoid it.  Some monsters give obvious clues when and where they'll attack and are easily dodged, while others seem to attack at random times in random directions and are thereby completely undodgeable.  It's extremely frustrating dying to these monsters or bosses over and over again when there's really nothing you can do about it.

You can overpower these fights by using up lots of precious items to restore the HP you lose after getting hit by these undodgeable attacks, but it's difficult to get your hands on these items so you never want to use them.  Using them already feels like a defeat.  Even if you win you lose.

But Tales of Arise is mostly a tale, not really a combat simulator, and as a tale it's doing fine.  I haven't seen much of Rinwell, but I've seen enough.  She's beautiful and has a high emotional voice.  She cares for her pet owl and struggles against injustice.  I suspect I'll only grow to like her more the longer the game goes on.  Rinwell is a nice girl, unlike Shionne who intentionally antagonizes everyone for God knows what reason.  Shionne is pretty, maybe not as pretty as Rinwell but quite pretty, but she'll never make my fictional character hall of fame due to that bad attitude.

Rinwell replaces Mint from Tales of Phantasia.  Mint doesn't have much presence, mostly she stands still and looks sad -- whether in the game or the anime adaption of the game.  I'm pretty sure Mint could only heal and had no offensive capabilities, unlike Shionne who's both a great healer and gunner, which is why it felt like she wasn't really there.  Rinwell has a much prettier and infinitely more detailed character design, a voice, and a visible role in the battle.  You notice her.  Actually she might be the most noticeable person in the game, the one your eyes always drag towards whether you intend to or not.

I was hoping Tales of Arise could replace more bad Tales characters but this is the limit.  Three characters is already a great job, Arise worked out exactly as I hoped it would.  The remaining replacements must come from the other forthcoming games, I'm sure some of them will have formidable candidates that can beat the worst of the current crop.