Some of you speak of the DRK class in FFXIV like you already know what it will entail. I will help you out real quick, you have NO idea that it will be an INT based class, you have NO idea what stat they will base any of it off of. You can speculate, but you cannot say for certain. Additionally, whilst I prefer a 2H sword for them, I am not against a scythe albeit being terribly cliche.

My personal preference, I will reiterate, I prefer my DRK to have a 2H sword, command a presence and tank like any self respecting man (or woman) in heavy armor would do.
I would envision them as a class that utilizes aoe dark spells to lower the damage received from targets around them and increase their damage/enmity

Kind of like a mixed bag of a warrior and a scholar with respect to the health and shields of each respective class.

Maintaining a rotation to basically keep those buffs/debuffs active at all times.