Leon, the
first DRK, primarially used spears and axes. Just look at his
proficiencies and most powerful weapon...
p.s.
My main problem with the shield idea is that it provides too much to defense in this game, unlike other FF games. Here with this one, I can see it possibly coming from a gladiator but changing the role entirely to DPS as every incarnation has intended the class to be a DPS role, despite unintended hick-ups, loopholes, or game unique customizations. I am sure they never intended NIN, WHM, or BLM to be tanks and I don't see that here. If they chose a previously tank class for a DPS role, I see a stance reducing its defenses and still wearing heavy armor (It'll just would be like dragoon armor really in effect).
If you can't take my opinion, read the wiki's description: