Black Blade +10 plus carthus flame or carthus rouge, quite nasty. Manikin claws, pontiffs right eye, Farron ring. Then play like its Bloodborne. I find rapiers to be reliable weapons for dex builds, it doesn't do as much damage as a straight sword or katana, but you'll get more hits in and easier to dodge out of. Quantity over quality. I'm currently working on an intelligence build that's kinda paying off. I switch off between a crystal long sword and a fire one depending on the enemies I face. It gives me a decent a mount of combat options.

I have always preferred the dex/fth builds. Gives you lots of options for your character.

Dex build with Gotthard Twinswords and Great Magic Weapon sorcery. Strength build with Black Knight Greatsword or Lothric Knight Greatsword