Think Dark Knight will have any HP-sacrificing abilities, for Solo or Off-tank roles?

[Krr]

I'm not against the change, and no, you're not breaking it to me. Earlier dark knights, such as Cecil, weren't tanky, he was a protagonist, and he had to go alone for most of his dark knight career.

Erm. Factually, these are the party members who adventure alongside Cecil as a Dark Knight, in order:

Kain (DRG), Child Rydia (BLM/WHM, minimal Summons at best), Tellah (BLM/WHM), Edward (BRD), Yang (MNK), Rosa (WHM), and Palom/Porom (WHM and BLM).

Cecil spends approximately ~30 minutes of the game alone, where he must walk across a desert to bring Rydia back to life. Rydia starts much weaker than Cecil, but becomes a very competent black mage and can spot as a white mage after one dungeon, wherein Tellah also joins the party with a mid-level-ish array of Black and White magic. During the intro dungeon, he is also accompanied by Kain, who is a superior damage dealer with Jump in nearly every respect.

Two and a half dungeons and one town event after we get Tellah and Rydia, Yang joins the party, and absolutely blows Cecil's damage output out of the water.

We can imagine or remember epic depictions of Cecil's character all we want, but he was by no means a stellar damage dealer in FFIV.

"Tank" does not mean "protector". "Tank" means "shock trooper heavy enough and good enough at face-to-face combat to keep enemies busy." Thus was the role of the NES FF3 Dark Knight, Cecil, Gafgarion, and similar. Thus is the role of our own Warrior class in the game - a heavily-armored berserker who's weight and power is difficult to ignore.

I would find it more of a lore violation that the vicious and prideful Dark Knights of FF lore would fight behind their enemy rather than face-on.