Found my old explanation of the "road of DRK's identity":

I think in order to make DRK "feel like a DRK", we have to explore the identity of DRK.

It was first playable in FF3, but most of the NA audience never played 3. So really, our first exposure was FF4, in the form of Cecil. Cecil as a Dark Knight could use the ability "Darkness" which cost HP, but did damage to all enemies. He had high HP and Def and could use swords and shields and heavy armor.

It didn't appear again until FFX-2 as a dressphere. There, it also had Darkness (aoe) and Charon (single target version of Darkness), and Arcana. It also had proof against most if not all status ailments. It still had high HP and Def.

It next appeared in FFXI as a DPS class. It lost a lot of it's identity here, as it was basically turned into a hybrid caster/melee. Could use black magic and stat-absorb spells, had access to early Stun and could gain TP really fast. Also lots of Draining abilities.

It appeared in FF: Tactics PSP version (war of the lions), and there it focused on HP/MP drain.



So the major themes of DRK have been:

-High HP

-High Def

-Darkness (sacrifice HP for damage or later HP/MP drain)

-Drain/Absorb

-Ailment immunity and or infliction/absorb



I think FF14's DRK actually fits those themes fairly well. We don't have the HP sacrifice part, but they changed it to MP sacrifice (the mp management mechanics). They kept the high HP and Def themes, as well as the Drain/Absorb aspects.

I agree with the other poster that the biggest thing is just getting rid of the Dark Arts spam. Not only is it annoying, but it trivializes the "lore" of the ability as well to have to spam it so much.