Dark Knight thoughts FFXIV\

"How does a Dark Knight overcome it's weaknesses through its own abilities?
What makes a Dark Knight different from the other tanks in terms of philosophy and ability implementation?"

Dark Knight's main weaknesses are it's dependence on abilities locked behind costly mp barriers (dark arts, unleash, dark passage) and the lack of innate physical tankiness.
The main tools for a Dark Knight to deal with these issues their high enmity generation from a boosted Power Slash combo, which gives the user the space to use one or more siphon strike combos to regenerate mana and several off-cooldowns which reward knowledge of the fight and what the dark knight has at it's disposal at the time. With proper knowledge of a fight, correct times to save mana or to spend mana because it will be quickly regenerate will become second nature and the player will be able to deal with the most onerous of resource drain.

Physical tankiness however is one problem dark knight's were built with and do not have a proper way to deal with this. Outside of the two bigger cooldowns (shadowskin and shadow wall), only 1 cross class skill provides a %based increase of defensive value. The other skill only gives parry, and can be upgraded to give evasion, both stats which cannot be counted on. Napkin math shows 30% parry is roughly an increase of 6^ (30% increase*20% reduction), which makes it relatively worthless, more so when it comes to large one hit tankbusters. To deal with this, I can only recommend gearing a paladin, who is built for such situations.

A Dark Knight is different from other tanks in that while paladins and warriors have some leeway when taking damage, the dark knight does not enjoy this same safety bumper. This means that to be played to the highest level, dark knights need to know fights inside out. Without such knowledge, a dark knight will quickly become a pool of blood on the floor.

The Dark Knight plays very mechanically similar to the paladin, with all of it's defensive power tied to off-global cooldowns. They differ from the warrior, who has a lot of reliable mitigation tied to offensive moves (IB and SP). However, Dark Knight has a larger variety of cooldowns to be managed (offensive, defensive and utility), as opposed to the Paladin who has very few offensive (2) or utility cooldowns (1).