Your thoughts on DRK as a Tank in the future?

[Reynhart]

As for the Job itself in the game, I found it to be the best iteration for it that I've used or seen yet. The Job's main trait was an ability called Adversity. For each increment of damage that the character would take in percentages of 25% I believe in relation to your max HP, your four primary attack and defense stats would increase. So Phys Defense, Phys Attack, and Mag Attack and Defense. They would cap at 150% of their start, and make it a great tank class in the game, if it wasn't designated as more of a DPS of sorts in the game itself.

What made it so excellent is that I could easily make it into a tank in the party just by shifting around gear, and making him two-hand a sword which would give him great offensive capabilities. With Adversity boosting it's stats the more damage it took, it propelled it's abilities means to do damage even higher. You couple that with another Sub-Job that lets it drain stats, and it could become a powerhouse, only having difficulty with enemies resistant or immune to dark damage.

Dark Knight wasn't a tank in Bravely Default. He doesn't have any attention grabing or protection skill, and several of its skills required to spend HP to do more damage.
It's not because you can use a heavy armor that you're a tank, especially compared to jobs like Knight (Protect other), Samurai (Supposed to be hit by the enemy) or even...well, I can't spoil the last one, but it's far more focused on defense, with things like Rampart or the enhanced damage reduce to Default.

Actually, you said it yourself, Dark Knight has "great offensive capabilities", and can become a "powerhouse" so...not a tank.

Cecil was very much your damage absorber, but as a dark knight it was always a risk versus reward thing.

Cecil was absolutely not a damage absorber. He was one of the sturdiest character in the beginning, but only because other party members are White Mage, Black Mage or Sage. (And his stats were absolutely pathetic)
You can clearly see the difference when he changes to Paladin, with a lot more Defense, a skill that let him protect party member, and White Magic too. And more HP at level 1 that what he had before the class change

Apart from that, I'm both disappointed and happy to see a Dark Knight tank. Dissapointed because DRK was the DPS I loved most in every game it appears, and happy because tanking is my favorite role in MMOs.