Nice and simple Dex Hex build that uses hexes as a supplement, not a one-shot cheese. Usable in NG, requires Sunken King and Old Iron King DLC
Scimitar +10 (my preference but you can use anything within the weight limit really)
Bone Fist +5
Black Witch's Staff +10
Black Dragon Torso & Head Stones.
Rings: Third Dragon, Chloranthy, Flynns and Simpleton's
Dark Weapon, Dark Storm.
Could use Resonant Weapon if you have the spare souls.
There's a third slot which you can use for whatever (extra casts of Dark Storm, Dark Orb, Scraps of Life, Warmth if you are fight-clubbing)
RB spam the scimitar, back-step and attack with the bonefist. If you get a parry or backstab then you should try and cast Dark Storm during the recovery.